Few days back, I landed in Canada (Detroit Windsor Tunnel) by a rental car, spent some time in the city and came back to Detroit using AVR. No issues. Few points for everyone's benefit. 1) when you take the road to Canada, just before the toll plaza ($3.50 payable by cash/credit card) there is immigration office on your left hand side. You will find many cars parked over there. If you want an exit stamp in your passport or need special registration, you need to park your car over there and don't come out until an officer comes to you. You will be directed to follow the path to the office where you can perform Special registration. If you want to come back to USA using AVR, tell the same to the officer and he will issue you a new FIN number. You will be asked a few general questions, and will be fingerprinted as well. Once done, take your car, pay the toll (US$3.50) and drive down. On canadian side, you will be asked the purpose of visit. If landing, they will guide you to the immigration office (on right hand side). Park your car, go to the office. They ask for the landing papers and key in some information in the computer. They will also write some information on your landing document, make you sign it, and put a copy of the document in your passport, This is your temporary PR card. Then you need to declare the goods you are carrying and also the goods to follow. They put a stamp on your B4 and B4A forms and will issue you a yellow slip that you can show to the customs officer to release your car. You are free to go now. I landed on a holiday and couln't apply for SIN, Bank Account or Health Insurance Card. Anyways, when I go there again, I will apply for all of the above. After spending a couple of hours in Windsor, decided to go back to US. Paid USD3.50 at the toll plaza and entered the tunnel. No questions asked. Once on US side, I was asked about the purpose of visiting canada and that if I have something to deeclare for customs. I told them that I didn't buy anything from Canada. The office checked my passport and Valid I-94, issued me a yellow slip, put it on my windshield and contacted someone in immigration to escort me. I was directed to the same office where I did my special registration before. Same officers were there and hence no problems. They advised me to get a visa for future travel. They also mentioned that AVR is just for bordering countries and if I travel somewhere else, I will not be allowed back in US solely on I-94. Again, they confirmed my I-94 details, but didn't ask for paystubs, employer's letter or anything else. They put an Entry stamp in my passport and that was it. Just one advice, be clear in your mind and say the truth, you will not have a problem.