Thank you for your reply.

In all honesty, I bought the car, knowing that it would need some new boots within a few months. I have no information with regard to the current alignment numbers, but have taken onboard what you have said about the toe in etc

The car doesn't have a spare wheel, and the space under the rear floor is really handy for storing things like my electric tyre pump, various tools that I like to have to hand, some jump leads and a few other things, that would otherwise be taking up a lot of space. I have to admit that my main criticism of the X5 is the general lack of storage space, my (4) Mitsubishi Shoguns (known as Montero in USA) that I have owned and driven over the last 11 years all had plenty of places to hide stuff away, but of course they are very agricultural in comparison to the luxury of the X5 .

I have mulled over the pros and cons of not having a spare, and have read so much information, the authors of these topic related posts seem to repeatedly say how the car was designed for these expensive rubber bands (very wide but very low profile), and that the ride comfort would be compromised by changing from run flats to normal type tyres.

Obviously, I am aware that people have their opinions, and there are many people out there who have far more experience than I have with Beemers. This is only my second in nearly 40 years of driving, and my first with these "run flat tyres".... so that is why I am asking for people to open up and say what they have experienced with them. I am not against going to buy a spare from a scrappy somewhere, though which size tyre to put on would also be an issue due to the rears being wider than the fronts. My back pocket is likely to benefit from using normal type tyres, but if it causes any issues with insurance or whatever, then of course I would have to take that into consideration also.

I expect that I am looking at this with an enhanced amount of caution due to the many posts that I have read...... things like, make sure that the tyres have a "star" and that they are BMW recommended etc..... I just feel that £1000+ is a lot of money for 4 rubber bands that are only expected to give 12,000 miles...... I have put 3 full sets of tyres on my current Shogun in the time that I have owned it, and I have driven it for just over 100,000 miles in those 7 years, I think you may well understand what I am saying, and I want to get it right without spending even more of my kids inheritance, and when the time comes, they will be the ones that choose my last home..... so need to keep them on side :-)