Having just purchased a Z3 (pick it up tomorrow) and just joined this forum, I was reading through old threads and posts when I came across this one. It's not too old so I figured I will add my 2 cents worth.
Yes, I am pretty sure they will go up in value, and I am talking all the models. I have collected and rebuilt old motorbikes for some years now and there is a pattern as to what happens.
I will talk motorbikes here for now, as it's what I know. Firstly anything that is a little out of the ordinary or not run of the mill is usually the first choice. The top model is always the first to go up in value. Talking motorbikes from the 70's a Suzuki GT750, about 10 years ago you could buy one for peanuts. As people who remembered them from their youth decided mmmm I might buy one to restore it. (Men like to restore old bikes, myself included). There is a valid reason for restoring, firstly it's not such a huge outlay of cash in one chunk, in fact most of the time you can hide this cost from the wife and she will never know how much you paid. secondly you can have many many parcels arrive and as it's all in small chunks of money you can again hide the real cost from your wife.
But what happens is when someone decides they want an old bike, they will always go for their dream bike, usually the top of the range.(let's use a early 70's Suzuki GT750 as an example) Many men from the same period (same age) will look to the same bike because that was the bike that was out when they were in their teens, they fell in love with it then. So as demand increases, so does the price. But what happens then? Well, MR EXAMPLE decides he wants to re-live his youth and buy his dream bike. He looks at prices and nearly faints, he has missed the boat! he realises he cannot take that much money from the life savings without his wife knowing, so he decides to go for the next model down which is much cheaper, enter the Suzuki GT550! This cycle will carry on until the 550's are too expensive so eventually people will look to the next model down, enter the GT380.and so on and so forth down to the Suzuki AP50 moped, (which are worth a small fortune now, I might add)
I believe the same happens in the car world, the first choice will always be the M models, the DREAM models, but just as in the example, when the prices get too high, it will be the next model down, then the next etc.
So to some up, yes I believe all models of Z3 will go up in value eventually, it has all the right ingredients! The kids that fell in love with it when it was out will eventually want one, now they are a little older and the family is growing up, and they have more disposable income to purchase their dream car.
There is one thing though that I have said many times on classic motorbike forums though. Unless you have large pockets, don't buy or expect to run an old bike if you cannot do at least some work on it yourself. Keeping an old vehicle roadworthy requires a lot of time and patience, there will be a constant need for repair's. Cars are probably more so, as they rust a lot more, and there are a lot of dirty bits under a car.
There are advantages to old cars too though, I have just purchased mine, knowing that I can run it for a good few years (not a daily driver) and enjoy it, but if I decide to sell it say 5 years from now, with any luck I will be able to sell it for more than what I paid for it. With my daily driver, modern car I loose thousands of pounds every year, hell you loose a couple of grand as soon as you drive it off the forecourt!
P.S. trying not to be sexist, it could also read "hiding the true cost from you husband" lol
