Clutch Ignition lock switch
 

Has anyone had to replace this switch ? It design is like the brake light switch; which I recently found can go south. I'm thinking of carrying one as a spare; if that switch fails, the car won't start....right?

Yes, it's easy to replace and is responsible for all sorts of electrical glitches. Keeping a spare is a good idea, although my boxster had no problem in 12 years, but my TT needed a new one as soon as I bought it. I think the weight of your key chain affects the longevity of the switch.

Just re-read your post and noticed you're talking about the clutch switch. I replaced both the grey and red clutch switches in my TT. They are also easy to replace. I was trying to figure out why my car didn't start all the time and changed the clutch switch and ignition switch and it fixed the problem.