Camry :: How To Modify Driver Seat To Sit Lower

I've already raised up the front of the seat with thick nylon washers, but the back needs to go down more now. I'm 6'3" with a horrid back and long legs, and there simply isn't enough thigh support. (down near the knees) I need the seat to be dipped low in the back and high in the front to be comfortable. Most cars allow for my preferred position in their normal range of adjustment, however the Camry does not. My head grazes the ceiling as it sits now.

How to get that bracket chopped down about an inch? Should I flatten it out, then drill a new hole?

I'm really open to anything, even unorthodox methods, as my comfort in this seat is more important to me than how the finished product looks to a rear passenger...as long as it's still a strong mounting point.