Hi Adrian,

GT1 is a system, consisting of hardware & software, used by BMW dealerships to diagnose, code/program the vehicles. This system is being phased out or has already been by BMW.

Some people/companies sell online and through ebay what I refer to as "laptop GT1". This is basically the GT1 software running on a laptop instead of the proprietary GT1 hardware. They cloned the system but it does not have 100% functionality of the original. For example, I don't think it supports all the different attachments like the original GT1 (like test probes or doesn't support wireless attachments).

Here's a link to some of mine and others experience:
http://www.xoutpost.com/bmw-sav-foru...aptop-gt1.html

Cost varies but its around $700 - $1000 for the complete system. The actual cost of the GT1 that the dealers use I heard run in the tens of thousands originally.

The value of these latop GT1s can be realized more by actual mechanics who will put the effort into learning the system. For myself, its enough for me to know its just a hobby.

Yes, they adjusted the sensor height to level the X. They did it as an un-asked favor, as at the time I didn't know how to use the GT1 to make the incremental adjustments, and they thought I'd want them to do it. I didn't find out until after they did it. Actually, I preferred they didn't do that. I was fairly confident there was a way using the GT1 but, at the time, didn't know exactly how.

I don't believe that its a big deal or that it may lead to problems. So, I didn't make them re-adjust. They were just trying to help me out free of charge. Bottom line, though, is the proper way to adjust ride height level is through the use of a GT1 or some equivalent - not adjusting the sensors themselves.

If you end up getting a laptop GT1, look at the link and search here and on the web. Lots of info. and will try to answer your questions as best as I can. Good luck!