Comedy aside for a moment, it is pretty scary how many so-called Cat2 installations there are about, WITH certificates, that are plainly not even close to the required standard.... You buy a car with a certificate of installation, and the first thing you have to do is take it to pieces and fit the system properly!!
When mine was fitted in the Sapph they wanted the car for a whole day minimum, and asked that if possible to have the option of holding on to it overnight.
You read soo many reports of people having problems and saying crap like "clifford (or whoever) are shite.." - 9 times out of 10 it's simply appaling installation that causes the problem.