Ariel Winter -- At War with Body Shop Over Benz

Ariel Winter blasted an L.A. body shop for taking months to repair her wrecked G-Wagon, but the shop's claiming she's just being a snotty celeb.

Ariel posted a scathing review of Paulee's Body Shop on her Instagram Monday ... warning her 2 million followers never to do business with them because the service is "incredibly rude [and] slow" and says the people are "unprofessional [and] intolerable." She says it took 4 months to fix her car. Ariel says if she could, she would give them a minus 10 rating.

Eric, the manager at Paulee's, begs to differ, telling us the car was only there for 2 months, and it needed $75k in repairs because it's a limited edition Benz and parts were hard to come by.

Eric says he still has the car because Ariel hasn't paid. It looks like he wants more than the $75k ... Eric wants Ariel to take down her rant against the shop.