Some pictures of the undercarriage body damage, only paint damage in fact. The rocks were a bit too big to go and drift around the first time, before I made a track with the broom, removing the bigger rocks (10mm rocks means 10cm scale rocks lol!) And the paint did not adhere very well on the galvanized steel used for the floor, it was peeling away as I was removing the electrical tape that holds the body in place
Also the interior ends up full of rocks, for that I plan to add some rubber pieces at the fenders, trimmed to fill the gap between the body and chassis. Also you can also see in the undercarriage pic where I ran the motor wires in the transmission tunnel lol I thought it would be neater than drilling big holes in the firewall and wires all around the cabin. So they are under the car, and ESC is in the trunk. I'll post pics of the interior soon.