Bro, Which Parts are you asking... Engine parts etc or Body parts,
Part related with engines are easily available, and about Body Parts, Most of the Shop thay dont have it, but you can get From Old market easily,
About Tunning, i can guarantee you that for a 2-3 years you will never visit any Mechanic (But yes for Changing Oil etc you should go)
and forget about GLI, Pak car never compete JDM's so Chill