My C came with a Cobra alarm / immobiliser and it seems to work very well – has 2 sirens fitted in different locations so it should be a bugger to disable in a short period of time (fitted by Canterbury hi-fi).
I’d also recommend a microscan system. You active a pager-type device and if the car door is opened (regardless of whether the alarm is set) the pager beeps. Added security of you have to park on the street given that most alarms are ignored.
Scott, I agree with you about the Dunlops. Get my car back tomorrow with new fronts and will email you after the weekend and let you know what their wet weather perfromance is like - it's bound to rain on Sat / Sun after being fine all week :D
Banana man / Nigel
This site lets you work our the speed differences depending upon which size wheel / tyre you have fitted.
http://www.fernblatt.com/longhurst/tyre_bible.html
It suggests that at a stated 70mph on your speedo you'll be doing a true 72.4mph. So at a stated 100 mph you're likely to be doing 103.5mph.
For what it's worth, I had a similar problem with my MK2 Gti 8v years ago. Tried all sorts and the only cure was a new head gasket (the old one was coming apart and bloked part of the cooling system).
Thanks for your comments / input.
I've had some BFG Profiler's fitted after running it on Dunlop SP2000's. Due to get my C back from the garage this week after the mother of all services that took over a week and a half. I'll let you know how I get on next week after a run up to Cambridge.