Check all panel gaps for allingment and consistancy. Check for dents, scratches and scuff marks on the paint work. Check underneath the car for transit damage (under side of side skirts, front bumper and floor rails) Check the spare wheel, jack, and all the other crap in the boot. Check all the rims and tyres for any signs of damage. Check all the door trims for scratches and scuff marks. Check all door sill trims of scratches and scuff marks. Check the dash and center console for any signs of removal, if you find any ask them WHY!! Check all leather trim on the seats/doors/gear boot and gear know for any signs of scratching or wear and tear. Check under the bonnet to make sure you have an engine, $9000 to get one if you dont :P Check all the fluid levels and make sure there is no leaks. Check that the paint in the engine bay is of satisfactory finish. Make sure that all your accessories are fitted. Make a list of all faults you spot then hand it to the salesperson and ask how they wish to fix them for you. :D