Just realised this is the same car I 'saved' on the Autotrader app the other day!
I think the relatively short MOT (less than two months left), plus a couple of advisories on the 2022 MOT (and no mention of if they've been fixed) is what is potentially putting people off, plus the fact it's the wrong time of year to sell. Though I still think it's a reasonable price for that mileage and the 3.0 engine.
I love my 2003 2.5i Z4 auto (91k miles at the time of purchase August 2022, and 96k today), but I made the mistake of buying cheap (£3,700) so buying twice, as it only had 1 years history and I've probably sunk close to another £3k into it now, in fixes and improvements, and it's a lower spec car (electric but not heated seats, no satnav and the basic sound system, though it did have factory xenons). It's getting closer to a well sorted car now, but it's always a dilemma knowing when to stop, as i'll never get that money back and long term I want to buy a lower mileage 3.0L example and probably a manual.
If I could turn back the clock and do my first Z4 purchase all over again this would definitely be in the running! Good luck with the sale!
P.S. I love that colour for what it's worth and it's one of the best rims on it too! Better than my dull titan silver!