I've seen quite a few in the last few weeks, all trade so far. I've only seen two that I'd be prepared to buy that were in good mechanical condition and the interior was well looked after. The reason for not parting with my cash was the first one was a very basic spec & not quite the colour I was looking for but in excellent overall condition. The second one was a low mileage (under 40k) and almost immaculate, but again wasn't quite the colour I wanted. I went to view it as I needed to compare an excellent example against the most recent Z4C's I had viewed. On hindsight I feel I should've made an offer but unfortunately it has now sold - snooze you lose!
One I saw two days ago was in superb condition inside and out but had what I believe to be a 'ticking' on start up and the gear changes between 1st & 2nd were pretty clunky. It may have been nothing but I wasn't prepared to part with my money on it.
In my opnion, many were 'over priced' (they had a large dealer premium on it). With the exception of the immaculate low mileage example all the vehicles I viewed are still on the market I believe.
The market seems fairly stagnant at the moment, maybe due to many different factors. But if anything the entry prices being advertised seem a little too optimistic initially, even with some private adverts pricing similarily to dealers.
Of course the above is only my observations (I'm in no way claiming to be an expert) and I've only monitored the market for the last 4 months or so.....
At the end of the day something is worth what another person is willing to pay for it!
