That doughnut cushion is not always the best answer. It makes your insides kinda drop through the hole and so puts stress on the vj internals. My experience...
I used to sit on one cheek, then moved to the other, a little forward, then a little back...
Also if you have an auto-box it is less of an issue. Stick shift requires more action, obviously.
I drove long before 1 1/2 month post-op, and it was OK apart from the discomfort after a pretty short while.
In fact I drove back to my place (~ 1 1/2 hours) just 1 week after my PIH return, which makes it ... 2 weeks post op, 3 weeks after the first main-op.
Axélle