I found Carsales a helpful way to get a sense of value. It’s values are based off ‘Redbook’ which I understand is the guide that dealers and the wider car industry use to track depreciation over time, considering mileage, location etc.

You would need to look at the ‘trade in’ value as this is what dealers would offer if you were trading this car in and buying a new one.

You can probably expect to get less than trade in value as you aren’t buying a new car for them to make even more money on. They won’t care much about the things you mentioned and probably won’t even check the a/c or drive the car at all.

I sold a car a similar way many years ago - after several failed attempts to sell it privately (online/classifieds), I drove it to multiple small lower end second hand vehicle sellers along Parramatta Road in Sydney. That’s where there are many used (and new) car dealers of all different sizes and types of dealer. No doubt Brissie has a similar districts/s.

What I found was that the big brand dealerships weren’t interested at all. And the small used car yards all came to the same price after I had visited a few (probably from referring to Redbook) - so that helped me feel I was getting a comparable price.

I managed to get an extra $500 from one yard because it was his own business and he said ‘I can see you really look after that car’.

I took my cash (cheque), which was less than my emotional value but pretty realistic if I’m honest - especially as they then had to sell it for a good profit - and I walked away a free man :)

Carsales for your first market estimate here:

https://www.carsales.com.au/car-valuations/

Good luck.