My audi a4 smells like burning rubber and its mostly from the rear...?

I was going down a road in my 02 a4 1.8t which is manufacturaly lowered and inch when i hit a pothole. All four of my wheels went through it. Nothing seemed wrong until i went home later that night. When i was pulling into my drive way it smelled like burnin rubber. I didnt know what it was. The next day when i drove it, it smelled like burning rubber when i turned on my heat. It didnt smell as strong as it did outside and it was mostly from the rear. When i popped the hood and tried to smell it, there was no smell there. Also when im driving my car, and let go of the gas it seems as if my car is breaking by itself and it begins to slow down slowly. Any ideas? I appreciate it. Thank you :]