As an investment a classic makes the most sense and for this sort of mileage will be easier rather than more difficult to maintain. If you're thinking of going anywhere, it's also imperative to check the luggage capacities of the cars you might buy. No problem with the Bentley. And a Boxster S actually has two boots, front and back. But the F-Type has a tiny and very shallow boot, which the optional space saver spare fills almost entirely. Had you spent £150,000 on a perfect 1961 Mercedes Benz 300SL Roadster in 2006 you would probably be sitting in a car worth £500,000 today. They're surprisingly good to drive as well.