welcome to the club :thumbsup:
my checklist- chassis no. is the same with ur manuals cover note
- check lamps, signal, high beam
- usb port working not
- any stone chip/dent around body
- ask SA teach u the dashcam operation
- check around view monitor is working or not
- ask SA teach how to play video to the roof monitor
- engine bay, any cover (penutup) already open and forget to close back
- fog lamp, see whether got gap or glass pecah
- aircond
- tyre repair kit at 3rd row is it there
- sliding door smooth or not
- leather seat, any colour different/defect
what to buy? suggestion only, depends ur budget- coating
- tinting (add 1 more dark tint on ur vkool tint, but will void warranty)
- tpms (tyre pressure monitoring system)
- OBD lock (to auto lock the car when u drive; due to regulations & safety concerns, all cars no longer offer auto lock)
- mesh sun shade can get from Shoppee or google Groovy Sun Shade
- spare tire (this one very subjective, some just buy a spare tyre n put at 3rd row (abit dangerous when car crash); some will buy a tire bracket and install at the bottom of ur car (below 2nd row left seat, there is a dedicated place to put ur spare tire, but u need to get the bracket. u can ask SA to intro if he got 'kangtao')
- floor carpet
- light bulb (if u dont like the fog lamp drl yellow bulb, can buy white bulb to replace)
- add ur insurance cover on rear windscreen
thats all i can think of now

Long list to digest... Thanks ya.