Quite often drive underpowered cars (Saxos etc) with stickers, loud stereos worth 4x the value of the car and under car lighting. Often seen going around in circles in a car park 'race'.
They also drive basic-model red or white Ford Escorts (usually B-reg) with fake RS body-kits and stolen alloys (with the serial numbers filed off), with aforementioned stereo and under-car lighting plus blue windscreen wiper LED's.
I seem to have been lucky with eBay. Lots of people asking me to end my auctions early (my record number for one auction was over a dozen requests to end my SX32 Pro auction early!), but not much trouble other than that.
Steve.