[doughboy]

Agree with the 'L' shape, but it has to be a reclined 'L' for me.

I always want to angle/tip the seat base further back and recline the backrest a little i.e. knees higher than backside. This keeps you cosseted and secure in the seat under braking, instead of sliding off or bracing with your feet and knees.

Cars with high flat seat bases feel like you're sitting on a bar stool whilst driving (ford are a particular culprit here)

For me (5'11") its:

Seat base right down front lifted up, then set the distance so your left leg is just bent at full clutch depression.

Then set the wheel distance such that your arms are just bent with your hands gripping the top of the wheel.

This usually means no legroom for rear passengers (well about 15cm max anyway) but that's tough.