Re: If you do have trouble with the RCM.
I had a problem last year which turned out to be the RCM. I had some trouble trying to get it fixed here (in the UK) and ended up sending it to a guy "on this forum" in the USA who tests it, repairs any bad connections etc and sends it back. All it cost was the postage both ways and a small charge for the repair. No need to buy a new RCM and no problems with it since then. Hope this helps.
Generally, my only advice would be to use the car if you buy one. If you SORN it and lock it away for months over winter (as I have done many times) you might end up with problems - that has been my mistake.