WD40 does work to remove light scratches from car paint.
The WD40 is an oil and when sprayed onto the scratches the oil fills in those light scratches which then make the scratches disappear and leave a shiny finish.
WD40 will not damage car paintwork and is safe to use on cars.
You can safely use WD40 to clean things off your car without damaging or removing any of the car paint.
WD40 works great for removing tree sap, bird droppings, grime and stuck on bugs on your cars paint.
Just spray some WD40 onto the grime, SAP, bird droppings etc and then use a sponge or a cloth such as a Microfiber cloth and wipe the grime or SAP etc away.
Then use some soap and water to rinse off and remove the WD40.
Rubbing Alcohol is also a good safe way to remove things from cars or vehicles while avoiding damage to the paint.
I've used rubbing alcohol on my car to remove Tree SAP before and it worked great and didn't damage the cars paint.
Just be sure to wash the rubbing alcohol off the cars paint after you clean it.