If it was me i`d be looking at the engine . An 08 should be spottless and shouldn`t have the older car smell of diesel or signs of leaks at all . oil, p steer fluid etc.
When you drive it it should have plenty of pull at slow speeds in higher gears almost as if your trying to make it struggle .
Air con should have no smells and should pull to temp straight away .
Brakes should feel assuring rather than hard work to slow car .
Check lights for moisture and cracks.
WEAR on clutch pedal is common on lower mile cars that have been taking granny to town and back since new and i would never buy a car that has excessive pedal wear coz you just know that granny can`t rev smoothly or change gears withoutbrushin the gears teeth .
Scratches around the boot inner entrance are signs of pets or scraping wheelchairs in / out . Door inners scratch up nicely aswell .
NEVER EVER TREVER buy a car that has had a tow bar fittedunless your the one doin it or its a RANGE ROVER .
FULL SERVICE HISTORY with repair work that is minimal but only coz it has not needed fixin` .
Also look at the filters if you can . Just to make sure that your garage is servicing it if they tell you they are the oil filter should be clean and the oil in the engine should be clear .
I don`t know how to fix em but i`ve never had problems with a car i`ve bought apart from the usuals , tyres , pads .
£12,000 Is a big pile o squirrels if you buy a duffer
ALL THE BEST MATEY