How can i remove overspray?
 

When the painter was painting our kitchen cabinet doors in the garage and my car was parked about 20 ft. away,he got paint all over the car.The paint is an oil base white.I called a local detailer who will remove it with Mineral Spirits.Will this product harm the clear coat or worse?

Get a claybar & clay the car yourself.
It is perfectly safe & you'll be amazed at the results. ;)
Btw. the painter owes you a case of beer. :D

The painter is going to pay for the paint removel,but the detailer is going to use Mineral Spirits.I don't think that is such a good idea.

denatured alcohol should not damage the paint
 

if the mineral spirits he is using are mainly denatured alcohol should not damage the paint in any way. Since the overspray is fresh and not fully cured, he will likely soak a rag in the spirits and wipe down the car, this will remove the overspray quite easily, just make sure he does a thorough wash and wax afterwards as all your existing wax will also be stripped off.

This is the key.

Overspray
 

I had the same problem just after I bought my new Explorer. Detailer used diiluted mineral spirits to remove overspray. Paint is now over ten years old and still OK. Only problem was with the black finish on the wiper blades which has developed white spots, but that's not a big deal to fix.