I bought a fixer upper, the latest owner painted it black with spray paint......The original color is right under that untouched. The black is flaking off. Is there anyway to remove the black without destroying the red under it ?

 

Acetone and a cloth. Maybe a scouring pad. Just acetone eats flat black and will leave the factory clear coat largely untouched.

 

Only way thinner and a cloth will work is if you are the luckiest person in the world and have MANY hours and gallons of acetone. It is not worth it and the end result IF you get real lucky is the red paint underneath will need to be buffed out atleast. You will likely end up damaging the underneath clear coat as well. You can also try 2000 grit sand paper to see if the black will come off any easier first and then just buff out the whole car. You're better off getting a new paint job - Less headache without the hours of work that might end up in a new paint job anyways.