Yes, BMW offers its own wheel and tire insurance. They will likely try to sell it to you at the time of your purchase. Prices I have seen are much higher than the $646 for three years that your old company is now quoting. Three years of the BMW insurance is likely in the $900-$1,000 range (3 yrs coverage) but it does not have a ceiling... Also keep in mind that the BMW offering does not cover cosmetic damage like curb rash as I recall, only major failures like a bent/cracked rim.
I have it on my car and have only replaced one tire with a nail in it, no questions asked. With ten months of coverage left it seem like a money loser for me though the insurance on my wife's X5 paid or itself and most on my policy given the number of run-flat tires she went through!
Edit: Keep in mind that the price of the policy is negotiable, like everything else!
2011 Space Grey E90 M3, DCT, Comp. Pkg.
1997 Z3 2.8, Artic Silver, Tanin Red interior, MT
1974 2002tii, Inka, MT
Last edited by kscarrol; 01-14-2013 at 07:37 PM.