There are alloy braces inside the wheel arches from both rear corners to add stability and the front lower part is 10mm ply as this can be easily changed when damaged. This is roughly 10" deep and is just to take any impacts and add some strength to leading edge. This was sprayed black although on a road car it may be possible to use something like carbon sheet which wont take such a battering! I then used some edge trim between the two to give a nicer cleaner edge. Hope that is of some help!
hi mate, if you decide to have a crack at making one yourself feel free to ask questions. It really is a piece of ****. Basically its a sheet of 2mm alloy. Lay the bumper on it and draw round the bottom lip, Draw an identical line 2" further out. and measure back from the leading edge of bumper to just past where the bulkhead meets floor. This gives you the depth. Then i cut out for exhaust and clearance for the wheels to turn. I welded some pieces of box section with plate on the ends which i tapped on to the rear of the subframe to accept the rear of the splitter. Then i mounted the front of the splitter to the lower intercooler frame etc. This was held with rivnuts. I used alloy angle to make supports and to bolt the upright part which can be seen in the pic with large rivets holding the two pieces together.
You scratched his bonnet and he forgave you
Im doing ok thanks, now ive had my broken back bolted back together im going to try and get to the next meet.
Glad you are both good