Hi, I've read here many recommended fixes for a dodgy unit, but I'd just like to make one (hopefully) helpful suggestion ....try a new car battery first, before replacing the unit. My unit frequently died, often for long periods, but would then work again for a while, before shutting down again. I was about to replace the unit (main dealer recommendation) in order to sell my car, but the battery (less than 2 tears old) was replaced first, and hey presto, the unit worked again, and has not acted up since. Someone posted before about Skodas being temperamental where electrics/batteries are concerned, and they are!
It should be worth a try, and if it works, it's a cheap fix!
Great forum, thanks for all the tips