Mr Tidy said:Hi and welcome to the forum from a Coupe addict.
FWIW I would be looking for a Sport model rather than an SE for the M-Sport seats alone. Used M-Sport seats typically sell on here for £600/700 or so, although some SEs had them as an option and some may have been retro-fitted with them.
Both the linked cars look strong money to me but the A/T one looks to have a better spec with heated seats and Bi-Xenons which would both be expensive to retro-fit. It also has Cirrus Aluminium trim which is pretty rare, but IMO is much nicer than the standard Brushed Aluminium trim. The A/T one may have a slightly higher mileage but N52 engines cope well with high mileages - my current daily 330i with the same engine has done 120K and still pulls really strongly and happily revs out.
The electric water pump on N52 engines will fail, but how long it lasts seems pretty random. My first Z4 needed a new one at 60K, my 2nd seemed to be on the original pump when I sold it on 91K. The main issue is that when the pump dies the engine overheats in less than a mile, although it can be driven a bit further in "limp" mode. So some people fit a new pump to avoid needing to rely on a recovery service! And new pumps are expensive - BMW charge over £500.
But you can buy the same Pierburg pump elsewhere for £250/300.
Some Coupes suffered from rusty tailgates so that is worth checking. Just open it and check around all the edges.
It may not be too near to you and isn't quite OE but this one is £6K cheaper:- https://z4-forum.com/forum/viewtopic.php?t=140185
Good luck finding the right one anyway.
Thank you for the really detailed post.
The AT one is still on the original water pump, so that needs to be factored in.
North West Surrey