It's for sure WD40 won't hurt the paint.

 

Hi Drumhawk,
Since the tar remover ( WD40, gasoline, Tarminator,etc) is used to dissolve ( wiping) the tar and not allow to dwell ( sit) on the involved surface, no clearcoat damage will occur. Just like when you accidently drip gas on your finish when filling your tank, immediate removal causes only protectant ( wax / sealant) removal but clearcoat is perfectly intacted.
The only main concern when removing any tarry substances with whatever product you use is the potential of surface marring created by embedded particles like sand / dirt in the tar. Rub gently and make sure rag is saturated with tar remover ( ie gasoline) for faster dissolution and lubrication.

 

Hey man i work at a detil shop and we us stoner tarmanater all the time works great if ther is ALOT then i would go with gas just wash it off good after u get the tar off hope this helps

 

Thanks GreenGobbler

I was hoping that someone with body shop / professional detailing experience would chime in.