@Jambondrums The majority of this comes with buying a car that has had lackluster maintenance. Many of these cars are either heavily pampered or just simply not... Should be pretty easy to spot a poor example.
Some of these points are rare problems such as cold start rattles but sometimes people are selling a car with hidden problems or deferred maintenance knowingly or not... So it's better for you to be informed
Weeping/leaking cam covers (smoke/smell off the manifolds)
General oil leaks (look for dots of oil on the ground below the engine and gearbox)
SPORTS button works as it should - illuminates light on dash, stiffens dampers and on CC cars increases shift times/responsiveness of gearbox
Heater matrix (check for dampness in the passenger footwell towards the kick panel, also the windscreen/rearscreen will constantly mist up with a soapy/slippery consensation)
Make sure windows/seats and general interior electrics all work ok
AC should blow ice cold even in warm weather - if not usually just needs a regass but can cause problems if left unattended
Brake discs in good condition (the OE alternatives can be hard to source if you are not involved in the various forums/clubs and the stock discs are very overpriced so occaisionallly people run ruined discs)
Annual service regardless of mileage and no major services skipped - most important is recent history
Cold start rattles from the engine and underneath the car - various causes
Rust, any rust on the body walk away (i.e. wheel arches). Subframe rust is more difficult to see without getting the car on a lift or taking wheel arch liners off.
In the UK the nearside of the car (or LHS) look underneath just along from the side skirt, check the brake lines. They are made from steel which rust incredibly easily and it's a big job to change the rears
While driving check the function of the CC or manual transmission. Slipping under full throttle at high revs and between gears can indicate worn clutch. Jerky-ness when pulling away (or heavy clutch pedal with manual) suggest worn thrust bearing. If you get a loud honking noise from the clutch when pulling away when cold that's the spigot bearing...
Manual and CC have the same hardware in terms of gearbox, CC has a robotised actuator that does the shifting - the car is a transaxle design with a torque tube and gearbox at the rear. The gearbox and diff are in the same housing and share oil so check for drops of oil on the floor at the rear of the car as well
While driving check for clonking noises from the suspension. If from the rear sometimes it won't be the suspension but a worn bearing on the differential which is very difficult to identify but it makes a certain banging sound when driving on rough roads
Check the condition of the alloy wheels, mine had buckles causing vibration at speed and flaking paint - they needed a full restoration.
Check function of boot ancileries Inc cabin light and if the tailgate lock opens with the key as it should
Sticky buttons... I would not be put off as it has happened to 100% of the cars made in this era by Ferrari/Maserati/Lamborghini. I haven't sorted all of the sticky in my car yet as I want to focus on straightening my car out mechanically.