I used to bring integrales in from Italy in the early to mid '90s, it was more difficult to get them out of Italy than to register them over here although it was a different procedure each time, the main things to do are fill in the vat 414 form, mot the car inculuding putting a sticker over the speedo in mph and swap the rear fog light to the opposite side, then go down to your LVLO with all the relevant import papers and apply for tax, i'm sure it will have changed but like I said, it was more of a pain doing the paperwork in Italy and I have family there that understand what to do!
To get the car out you had to put it on temporary export plates and give the exact route you were driving out of the country, if you dared to deviate from it and got caught they would confiscate the car from you at the roadside!
I once got stopped at about 11.30 at night approaching the alps, i had a 'grale full of spares that it came with including a spare set of seats, they were telling me that my paperwork was incorrect (I had been over there two weeks sorting it) so we got into a heated disscusion which ended by them making me empty the car of all the spares so they could look inside then they drove off laughing leaving me with i pile of bits to put back which took me about an hour.
I would do it again if I had to though.
Good Luck!