What to Do When the Paint on the Car Roof Cracks from Sun Exposure?

[RoseRose]

First, check if each door is properly closed by opening and then firmly closing them. Next, inspect the door sensor switches one by one to see if they are malfunctioning, and replace them if necessary. If the doors are confirmed to be securely closed but the sensor switches cannot be checked, it is recommended to visit a 4S shop to inspect the circuit and carry out repairs. A continuously illuminated warning light indicates that the door is not properly closed.

[ColemanFitz]

When I last washed my car and found the roof covered in sun cracks, I was stunned too. There are three types of cracks caused by sun exposure: shallow ones resembling spiderwebs—they're noticeable to the touch but not deep, and can be fixed with polishing and waxing. If the crack is deep enough to fit a fingernail, it means the primer is damaged, requiring sanding to smooth the crack before applying filler. The worst scenario is when the paint starts peeling—those areas must be completely stripped and repainted. I recommend testing the depth of the cracks with your fingernail first to decide on the treatment. A word of advice: avoid covering cracks with a car cover in summer, as the trapped heat and moisture can worsen the cracks faster. Using a sunshade for temporary protection is a safer bet.

[StLucia]

Sigh, my neighbor's car roof is cracked like a tortoise shell. The mechanic gave a diagnosis plan: the depth of the cracks determines the treatment method. Hairline cracks can be directly polished to restore the gloss, obvious cracks require local sanding and filling with resin, and the most severe peeling areas must be scraped off and repainted. But here's a little tip for you: after repainting, avoid parking under trees for the first two weeks, as tree sap and bird droppings can leave permanent marks on the soft paint. If you're not repairing it immediately, applying a liquid car wax containing silicone oil to the roof can serve as a temporary raincoat to prevent rust.

[SanKatherine]

I totally understand the pain of parking outdoors! Cracked paint on the roof is not only ugly but also prone to rust during the rainy season. I've seen the repair process: shallow cracks can be fixed with machine polishing, while exposed primer requires sanding and applying body filler, and peeling sections need complete removal. The key is the painting process—a repair shop without a paint booth is a no-go, as air-drying results are three times worse. Last time I got a touch-up, I followed the mechanic's advice and applied a fluorinated coating agent monthly, and it hasn't recurred in two years. By the way, automatic car wash rollers can tear open cracks, so hand washing is safer.