Can u return a used car you just signed fir loan?

Just traded my mini van in bought a 07 trailblazer SS....just realised it is rearwheel drive.....I cant drive such here in winter. Didn't pay cash but signed loan papers which were to be held .I wrote him a check..getting my own loan so he was holding check for three days....not turning in his papers or cashing check. Can I return this vehicle without losing money? Will they give back my van???