Newly released position statements from Porsche outline how to properly repair or replace bumpers, rims, and windshields to avoid safety risks. 

Damage to bumpers could impact advanced driver assistance systems (ADAS) such as warn and brake assist, intersection assist, park distance control, lane change assist, rear turn assist, rear cross-traffic alert, and exit warning, according to the bumper position statement. 

“If damaged bumpers are not properly repaired, painted or wrapped, this may affect sensor operation and give incorrect feedback to the driver, thus increasing the risk of an accident/collision,” the statement says. 

Restrictions in the radar transmission area include: 

• • Bumpers must not be painted
  • Bumpers must not be covered with car wrappings or decals
  • Cracks/breaks in bumpers must not be repaired by
  • Plastic welding

The statement asks repairers to remember: 

• • Always follow the repair guidelines, painting instructions, and specifications approved by Porsche
  • When replacing bumpers, paint and fit parking distance control sensors in accordance with the repair guide
  • Only paint primed bumpers (spare parts) with paint systems approved by Porsche
  • Cracks/broken bumpers in the wheel transmission area must not be repaired

A Porsche windshield position statement says camera-based driving assistance is one of many features that can also be impacted by improperly repairing a Porsche windshield. 

“The original glass used on Porsche vehicles as well as the adhesives system and expertise in the workshop guarantee optimum fit, function, safety, and structural integrity,” the statement says. “The quality, performance, and safety of aftermarket replacement windshield and side glass may not meet Porsche exacting specifications. Only by using Porsche-approved replacement glass you can be assured of the fit, function, safety, and structural integrity of the repair.” 

Only OEM adhesives approved by Porsche should be used for glass replacement, the statement says. 

“These are precisely matched to the corresponding bonding substrates and made for the conditions in the workshop environment,” the statement says. “Adhesive systems that are not approved can lead to a non-functioning bond, which in turn represents a potential risk for the customer.” 

The statement says that not following Porsche requirements on windshield replacement can result in poor performance of key safety features and reduced customer satisfaction. 

Key features include: 

• • Camera-based driver assistance systems require complex calibration. In case of deviations, function impairments or threat to the driver can occur.
  • Crash/Stiffness: The windshield significantly contributes to the stiffness of the vehicle and also plays an essential role in case of a crash. Certain legal crash requirements can only be met with a correctly bonded windshield meeting the strength requirements.
  • HUD: The visibility of displays in the HUD depends largely on the coating of the screen.
  • Acoustics: Special acoustic glazing offers increased comfort, especially for our BEV buyers. Special LSG glasses ensure the corresponding acoustic damping.
  • Cold and heat protection: Coatings and films within the LSG glazing provide protection from both heat and cold. Replacement with non-OEM glazing that does not meet specifications can result in loss of comfort.
  • Antenna functions/antenna transparency: The windows serve to connect the vehicle with the outside world by means of integrated antennas. Also, coatings must provide a certain degree of antenna transparency in order for private smartphones to still have sufficient reception.
  • Tint level/color matching: The tint level, e.g., for privacy glazing, must match the rest of the panes. A different appearance would quickly be noticed by the customer. In worst case, over-tinted windows could also exceed legal limits.
  • Replacement of panes: Unlike, for example, bolted joints, there is no possibility of quality control for bonded joints after repair. Therefore, it is crucial for the work to be carried out in accordance with the repair process prescribed by Porsche and for the personnel carrying out the work to be appropriately trained.
  • Use of OEM adhesive: Adhesive systems are precisely matched to the corresponding adhesion substrates and the conditions of the workshop environment. Adhesive systems not approved by Porsche might lead to a non-functioning bond, which in turn poses a potential risk to the customer. In addition to the previously described rigidity and contribution to crash safety, the windshield also supports the front passenger airbag. Improperly executed bonding thus poses a potential risk of injury, especially to the front Passenger.

Porsche also says that any repair work on the material structure of their rims can represent a significant safety risk. 

“The development of Porsche alloy wheels sets the highest standards for weight reduction and performance,” a Dos and Don’ts Guideline released by the company says. “By reducing unsprung masses, we are able to enhance vehicle performance and improve traction. Porsche works directly with the manufacturers using a flow-forming or forge procedure to produce rims with minimized wall thickness and optimum stability.” 

It says repairing mechanical damage or reworking Porsche rims is prohibited. 

The retouching of minor paint damage is the only thing allowed, the guideline says. Repairers should also thoroughly check rims for prior damage or repairs and patiently inform customers why their rims must not be repaired. 

Porsche also gives tips for recognizing if rims have been repaired in an unacceptable manner. This includes: 

• • Paint coating: Measuring the thickness of the paint coating. Looking for differences in the color tone and structure of the paint or comparing polished/burnished areas of the rims with one another (similar to checking the bodywork for repainting).
  • Rim flange: Measuring the rim flange after removing the tyre to check if the contour of the rim flange still corresponds to the original contour.
  • Different polishings: Polished rims may show differences in the transition from the polished area (spokes on the visible side or exterior flange) to the spoke edge or the area where the polishing stops. On trimmed rims, the grinding pattern stops towards the center of the rim. Wheels that have been completely polished, i.e., up to the hub cap, may show geometric differences in the hub area compared to a rim that has not been reworked. Diamond cut rims may show differences in the transition from the high gloss area (visible or external spokes) to the spoke flank or the end of the diamond cut. In the case of fully polished wheels, geometric differences in the area of the hub may be visible up to the hubcap when compared to a non-remanufactured wheel. 

New Porsche position statements can be found on the Porsche Partner Network under the collision centers forum. 

A Collision Industry Conference Parts and Materials Committee discussed the complexity of refinishing vehicles as technology advances during a meeting in January. 

Benito Cid, Mercedes-Benz USA collision programs manager, said the company continues advancing technology that uses sensors, cameras, radar, and more, included as part of the technology suite in its Level 3 automated driving feature, Drive Pilot, in California and Nevada in 2023.

“All of these things require a clear line of sight,” Cid said. Ensuring the repair process and products don’t interrupt the line of site of those systems is why “looking at the procedures is even more important at this point.”

Repairers can’t repaint some parts with sensors, Cid said. Sometimes, replacing the part is the only option.

Other colors have a maximum amount of layers of coating such as primer, paint, and clear, he said. Some of these parts can only be painted one additional time.

Andrew Batenhorst, Pacific BMW collision center manager, elaborated on how his shop has developed a repair planning process to account for color identification and information gathering to help avoid timely or costly missteps.

BMW offers clear standards for refinishing near sensor technology, he said. This includes a flow chart that instructs repairers to follow one of three process conclusions.

Those processes include:

• • Process A, for minor repairs only, states no sand through as primer and base in the radar beam area is not permitted. It also says to only apply clear coat evenly over the entire bumper.
  • Process B allows for refinishing of the entire bumper with an even coating of base or clear coat. No primer or repair is allowed in the radar beam area.
  • Process C requires the replacement of the bumper.

“More often than not, I am seeing Process C where we are replacing bumpers,” Batenhorst said.

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