check for wet carpet and sound deadening, assuming the engine is reaching temp properly, cud be heater matrix, if cars not reaching temp proply then its cud be thermostat, and as for the alloys, ive got a nasty set of tsw venoms in 17" that every car owner shud hate so i wud be doubtful if ud like to purchase them, unless ofcourse u want to get them refurbed and still be left with turd looking wheels that eat kurbs