I think some of that happened because a Bonneville weighs about 4000 lbs vs a Regal (~3600 lbs) vs a 2 door GTP ~3300 lbs. I'm sure your foot didn't help either, lol, but I think it was the weight of the car. Surprised they didn't put the 4t85E or whatever's in a Cadillac Deville or STS. My friend keeps telling me I should get an adapter to put that transmission in instead.