The DRL's can be turned on thru iDrive. I did this in my 135i and it passed all inspections. I might have to change these purple ones though beforehand.
The speedo is already in miles and kms so that part is ok and that is it. I've had a warranty claim on my 135i with the brakelight LED and center brake light and they honored my warranty even though it was a USA car.
If you search around, you'll find that BMW Canada does try to charge you for compliance work if you call them and ask if your USA car is still covered. They'll tell you that you need to buy a speedo from them etc. and this will run you a few grand or so. But I'd recommend NOT to do this since whenever a friend or myself brings up a BMW, once it passes both inspections and is actually registered, you can drop by a few diff BMW dealerships and ask if your car is under warranty. I did this and they all said yes. There's no 'compliance letter' needed, nor compliance work.
Technically, we should not be able to turn off our DRL's but the people that do the inspections never check for that. There's only three different car brands that will not honor the warranty (I forgot which), but most will - although some brands might make you buy a speedo. I forgot if USA porsches have kms written on the speedo.
From personal experience, I know Audi's are absolutely no problem, and my BMW hasn't been a problem. A friend of mine tells me that Lexus, Land Rover are as easy as Audi also. To find mine, I just keep my eye on cars.com and autotrader.com and at least once / month, you'll see a great deal pop up.
The best deals I've found were a used Audi at a BMW dealership or a used BMW at an Audi dealership where someone brought in one as a trade in for the other! I guess they're rivals and want to liquidate the enemy. I'd stick to brand name dealerships.