I think my car is really messed up. I first noticed it when heading back to school in August. Whenever I'd travel up hill while accelerating, the car would make a jerking motion. It seems to only happen between speeds of about 40-60 mph. The jerking motion also happens occasionally when I'm sitting in traffic. At first I thought it might've been bad gasoline, because it happened right after I filled up, but I've refilled gas since then and it still does it.