I fitted boot lights about 18 months ago with the only problem being the boot was showing as opening and closing on the dashboard, with the mechanism sounding as if it was trying to open. As above I had a message saying 12volt battery low drive car to charge, drive car OK that day no more 12volt battery messages, next day I opened the offside rear door, then went to open drivers door, it wouldn't open, rear passenger door and boot were all that opened. I climbed into drivers seat, had the battery error, but started car and drove a few miles to charge battery. Car was with Skoda for a day and a half, it's now functioning correctly. The garage advised me to change the lights back to original ones, so I did this. Garage said battery and alternator are both fine.