I brought my 2008 TT Coupe into Canada in September 2010 with a little over a year of warranty left on it. I had lots of warranty work done on it before the four years were up. The local dealer had on-line access to all the service records done by the previous owner in Chicago, which was great because the warranty book had no stamps in it.
The owner had purchased Audi Care in the US, which was not honoured in Canada, but my dealer pointed out that Audi of America would honour it if I took it to a US dealer across the border, and it would be worth my time since it was a $1500 scheduled maintenance.
I had to get Audi of America to talk to the Service Manager in Bangor (who claimed that Audi Care could not be transferred to a new owner) and in the end, all went smoothly.
2016 TT Coupe S-line, LED lights, navi, driver comfort, B/O, Mythos Black
2008 TT 3.2 Quattro Coupe S-tronic all options
2006 A4 Avant 2.0T Quattro 6 Speed
2002 A4 1.8TQM Sport
1999 Nissan Maxima ES
1987 Nissan Pathfinder SE
1984 Nissan 300ZX 2+2
1980 Nissan 280ZX (10th Anniversary Edition)
1978 Datsun 280Z 2+2
1975 Austin Marina
1972 Yamaha 185
1965 Sears Allstate