Done nowt to the car itself, but just about to dip my toe into the pool of Dashcam ownership (again).
Gone for a Thinkware F770 hardwired dual camera system (and a second for the wife's A1), and crucially, this one seems not to run hot and has an overheating protection system built in. Looks just as subtle as the Blackvue 650 I had last time, good day and night camera performance (Sony CMOS EXMOR camera system) has car battery driven voltage shutoff (so no need for a magic box) and is full HD front and back. It also has lane assist and (for the wife's A1, no point in activating it on the Golf) it can annoy you with warning that you're too close to the car in front if they suddenly step on the brakes.
Someone put it on HUKD at £229 in a Black Friday sale, but managed to find it through a proper UK retailer for £209.
http://caraudiosecurity.com/f770-front-rear-dash-cam-full-hd-speed-camera-wifi-32gbFitment should be just as easy as last time, without the addition of the magic box - i'll just have to be more careful with the bootlid cable trunking clips this time!