I have a 98 SL600 which I brought up to Canada recently, paid the GST and Import Tax at the border. In order to get compliance to register in Canada, this model and year have to do the following:

1) Letter from MB USA that there are no warranty issues, this car being a 98 was straightforward and I have letter of admissibility.
2)Compliance letter from MB Canada. $500 fee to get letter, after inspection of work done, see 3) below.
3)Install daytime running lights and get new symbol strip put in (stupid, but the "check engine" and "brake" symbols need to conform to ISO standards)
4)Get RIV inspection and pay fee. (Canadian Tire or other accredited inspection service can do this.
5) Drive away with one of the greatest cars MB built in its day.

I still have the car, but am moving back from US and wish to sell. If you are interested in it I have it listed on kijiji.com (Nevada) and autotrader.com. All my information is on ads.

Cheers!