Run Flat Tyres

Hi There,

I have a 2010 BMW 320D MSports Auto. Had it since new Fantastic car, pulls like a freight train. I hate to say it, but seems to have as much towing poke on the road as my previous Land rover discovery.  I have just had to replace the tyres for the first time at around 20000 miles at a price at the best part of £1000.  I am thinking of changing to traditional tyres and a space saver wheel on the next change to reduce this cost.  My questions are:-

1. Does anybody have experience of a run flat puncture towing & what was the outcome?

2. Does anybody have any thoughts on a puncture when towing & using the BMW spacesaver wheel. Is this suitable for towing at all.

Thanks,

Carlos