Good, unmolested E30 convertibles are becoming increasingly rare. This might qualify for a classic auction, such as www.historics.co.uk (at Brooklands), or www.barons-auctions.com (at Sandown Park, Esher). Obviously you will have to pay auction commission, but you get your money quickly, don't have to advertise, and don't have to offer any uninsured (and illegal) test drives to private purchasers. Alternatively I could put someone onto you. But, of course, he'll be looking to buy down to a price on which he thinks he can make a profit. I think between £4000 and £5000. Someone will really want a good E30 325i convertible, and if you are lucky there could be two or three at an auction bidding against each other. I remember driving an E30 325i that had done more than 1,000,000 miles.