I went back to the plain nylon c hubs and i think that's working better . I got dogged off with the constant failure of the one way roller bearings in the front drive hubs so i drew up and printed some direct drive ones instead .
Also printed up a CF nylon front bulkhead , shown next to the plain nylon one .
Had a couple more runs today and the gears are still going strong , should have time for another run later .
Its quite a learning curve working out what material to use where , the C hubs and chain sprockets are better in the plain nylon , suspension arms ,gears and gearbox in CF nylon , top deck / chain guide ,battery tray and wheels are all fine in ABS and just the rear chain guide in PLA .
These are my experiences anyway but it adds to the complexity when selling parts , if its a car that's going to get used a little , raced or displayed you might want different quality parts .... more to think about .