FWIW - I have the Bridgestone Dueler H/L Alenza on my 2004 X5 (not run flats) and I love them. Very quiet tire, low noise, great in the rain, I don't even put on my snow tires to go to the ski hill with them (probably should tho).

We replaced our conti runflats on the 2006 325i after 9,000 miles. They were horribly noisy. We bought the BMW mobility kit for the 2006 - it has a air compressor and some liquid to put in a tire in case of a flat. That solved the issue of not having a spare. We did buy a used 325i rim and got a tire for it and take that along on trips out of town. However the downside is there's not much room for luggage left.

The BMW dealer here gives us a case of ass each time we bring in the 2006 with non-runflats and wants us to buy new run flats for over $1,300. We paid about $800 for Yokohama's.

Anyway, on the X5 - you can get the same Bridgestone tire I have on my X5 (in 18 inchers at least) for the E70. $203 a piece from Tirerack.com.

So it did not work for you? Was it a puncture or a big gash?
I imagine that it should work pretty well for punctures, but useless for wide gash.