You need to be in on a decent 3.0 within minutes of it going up. Literally. I missed one this week and I enquired after 42 mins. I've missed various others in similar circumstances. And this car is even more desireable.
Would eat my hat if this was genuine and still available.
Is it a Cat? It would still be cheap mind you.
I think you missed out on my "decent" Z3 3.0 M Sport! If you'd have viewed the car you would have bought it.
It would have been worth the six hour round trip. In fact knock half an hour off the return journey as you'd have been doing it in a Topaz Blue 3.0
And l know that you are well versed in Z3's from the work you do on them.
Don't be scared by a 5 year gap in the dealer service history. Particularly if the car is only doing a low mileage each year. If the owner has serviced it themselves, it can be better. BMW charge £400 for little more than an oil change.
You can generally tell by looking at/driving a car how it has been treated.
Most people are open to negotiation on the price if you think it is too high, but you need to be stood next to the car with the money in your hand!