[rallymaster]

Hello,

welcome here on AF.
If you expect to make seperated side skirts I would advice you to build them in modelling clay hardening on air.
Easy to sand and to correct if they don't fit perfectly.
If you choose plastic card it may on my opinion be more difficult to work with without fixing it to the body.
Or best solution is maybe to mix both methods: a plastic card part fitted with clay to give it the final touch and form.

For the wheels I think that I've recently seen something like that in Fujimi spare products range... Not sure.

Bye
Phil