I've been avoiding the issue, but I can't any more since my mom noticed and pointed it out to me yesterday..
Evan has what appears to be a flat spot developing on the back of his head

I try very hard to reposition him, lay him on his side or tummy fairly often (for naps, not at night, and only when I am near him), and to get some tummy time in when he will tolerate it. He sits in his walker a lot so his head isn't down, and he sits in his bouncer still which is softer on his head.
I think the problem is his carseat and our commute.. on a regular day we are in the car about 2 hours, which means he is in his seat for those two hours.. even longer now that we have to pick DD up from school in the middle of the day.. and that's not including days we have to stop for errands like going to the store or when we have appts for me, DD, or my FIL. I also tend to leave him in his seat if he is sleeping when we arrive at our destination.
Well as of today I am going to leave the carseat in the car during the day and just carry E in and out on our million trips (obviously not to the store though) and that way I won't be tempted to leave him in his seat if he is asleep... is there anything else I can do?? I am going to mention it to the doc at his next appt (Oct sometime) but our docs are quacks, can't stand them!