Edit : The following may have some duplication to the buyers guide I wrote some while ago so apologies....(speed/free typed with non cross checked info off top of my head).
I would ask seller in advance if they are happy for you to read the car for fault codes & if they agree I would take one to plug into diagnostic port. If they do not trust you maybe see if there is an indy happy to do this for a reasonable fee. Mindful it is a weekend viewing so the later option may not be possible to achieve. If seller says no to either option it may speak volumes re them or the car.
I would approach your inspection in the same way as any other vehicle. Paperwork, history, mileage & servicing verification, cosmetic and maintenance condition including that of inspectable parts like pads, tyres, discs. Check for matching VIN to V5c. Check for prescence & function of all keys ( 2 fob 1 valet, 1 wallet (Unlikely all will be present but you can maybe write to prior keepers later).
If something is powered electrically check funcionality more than once especially folding mirrors, pan roof & window operation. Check the gearbox cold warm and hot. Very important - Check auto, manual & sport mode plus kickdown assuming it is auto. When you kickdown listen for any knocking from rear subframe bushes. Check the outer front cv boots, inside of rear tyre tread to rears. Look for pas hose and header tank leaks, check last coolant and brake fluid change dates.check tailgate mechanism operation by fob and hand. Check heater fan for labouring and also engine cooolant fan. Look for water pump leaks, also check for smoke from turbo on a 3.0d. Check pixels on dash & radio if no comms pack. Check colour integrity of screen on a comms pack or nav equipped car.Check date stamps on headlamps...if later than car could be minor repair only but inspect further.check function of auto wipers if so equipped. (Sensor behind drivers mirror). Check heated mirrors both warm up with demiste on. Check roof li ing for tears. Check roof for out of sight significant marks Many buyers miss stone chips to a windsreen , don't be one of them that windsreen isn't a cheap item.
Check CD changer & also Radio reception on a scan of weaker stations, if fitted check heated seats. Check for a recentish dated sat nav disc (if nav fitted).Look for mismatched tyres. Check panel gaps, enquire when alignment checked (if ever). Check trim under mats for unacceptable damage. Check panels side to side for correct gaps and ask re any body repairs being happy to accept a decent minor repair (bumper &/or car park dinks). Check oil and coolant for contamination.
Try to drive and view others beforehand ideally a minter and a snotter (forget colour or trim choices)....otherwise it can be hard to evaluate relative to other examples.
Brake firmly from at least 70mph indicated - vibration means likely thrust bushes need changing. Ensure you drive on bumpy roads at some point and listen/feel for obvious knocks.
Do honest maths (have some idea re costs involved) , re sorting issues as many change cars to pass on future bills. Dont reject due to work needed but ideally cost to buy and sort shouldn't be significantly higher than market value.
Do not be distracted by seller or anyone accompanying you & do not take allow emotion, or good points to compromise your negotiation......be prepared to walk away.
Be mindful that if you indicate to seller you are travelling by public transport &/or with cash that it might cause seller to reel you in on their terms. Worth maybe mentioning if you are viewing another car or two otherwise seller will maybe dig in heels re the money.
May seem daft but take your licence & proof of test drive suitable insurance to avoid only having a passenger ride demo (though a lot can be learned re mechanical sympathy of seller by seeing them drive it initially).
Try to keep things friendly as viewing thoroughness is likely to annoy all but a seasoned seller. If they seem restless maybe explain they can leave you to crawl over it if happy & their time with you is an issue. A walk talk video call in advance might save a wasted trip.
Be careful - seems you may have almost decided to buy this specific car already.
Oh & darker evenings on us now.....never view in the dark.
HTH
