A few more updates:
The completed chassis for the blue car and the ramaining parts for the silver car.... seats, brakes, dash, etc...
Both are being built OOB. For the seats, although maybe not the best way to do it, I drilled out the center of all the gromets/rivets and then painted the seat flat black. The flat black has enough texture to allow a sliver colored Prisma brand colored pencil to be used to color/outline each rivet. It's not perfect but once inside the car and completed they look fairly realistic and it's a lot easier than trying to actually paint each rivet with silver paint or attach individual photoetched seat rivets.
Anyway, here are a few more pics:
