My dealer will sell me an extend warranty from BMW. They claim it is similar to BMW's certified pre-owned warranty. It adds 2 years and 50K. It has a $50 deductible and does not cover radio or nav. This brings the total coverage to 6 yrs 100,000 miles. They're quoting $2,249.00 US.
The other option they offer is Universal Underwriters coverage. The deductible is $100 but it does cover stereo and nav. The price for 2 years 50K is $2,389. The price for 3 years 50K is $2,528.
In addition to this they offer the BMW extended maintenance plan for another 2 years / 50K. They are quoting $1,295.
I'm probably going to go for the extended maintenance and extended warranty from BMW. This will get me about as covered as I can be for the first 100K miles.