Sure no problem! I left my WRX back in Canada so I have a car when I go back to visit.
Funny enough I bought a used VW golf Diesel because I really did not want to pay all that money on a gas. I could afford it but just rather put money elswhere. If I do stay a few more years, I will probably a Subaru Impreza Deisel.
From what I hear about modified cars, it is not so easy. From what my friend told me, you get a yearly car inspection from a goverment run outfit and the car needs to be to manufacturer specs to pass. How strict it is, not sure but swedes follow the rules so you would need to investigate. And not sure how that affects imported cars.
Buying a car here is abouy 25% more expensive, so might be better to import one in. And about the same for bar and restaurants!
Goteborg is a beautifull city, been there a few times and really enjoyed it! Went kayaking up the coast there a few weeks ago.
Work bringing you up here?