Hi Matthew, welcome to the forum and the fun world of C5s
There's already a few people on here that have tinkered with various upgrades ( petrol engine, and an electric C5 that can happily hit 50mph
just to name two ), so i'm sure if you go down the non standard route, youll find lots of helpful advice
I tend to keep all the underneath standard, just go a little bit different with the body colour
Darren