firstly ...he should not have driven ur car without ur permission...but then again..think about what sort of legal compensation u looking for ...a full tank of fuel? the legal cost will outweigh any sort of compensation ur likely to get...so best is to just stay far far away from that dodgy business....and let ur relatives, friends, neighbours, footy team, local grocer, drunks at ur local...and anyone else u might bump into... to stay clear of that place...word of mouth travels far and wide...and given time...u might just hurt his business enuff.