I'm afraid so and many of them (resisting the chance to say "all") are quite nasty.
I actually went down to Sovereign Cars after selling the Aero 8 to look at a Cobra. The fit and finish on the Dax and AK was quite good.
This was the one I went down to look at. The problem was I didn't fit in it - if you think the S1 Aero 8 is narrow, these are much tighter across the cabin. The DAX seemed a little wider and the width even seemed to vary slightly from car to car.
The one that was quite impressive was the ABSOLUTE PERFORMANCE built cars -
link . The only downside is they get quite expensive and imho, I'd rather have a new/nearly new Aero 8 for the same money.
I didn't know that you were a closet Cobra Replica admirer, personally I would not be keen to buy a second-hand Cobra as some of the ones that I have seen appear to have been thrown together.
However, a well built one on a properly engineered chassis makes an interesting car, though I agree with your point about the cost.
RAM Cobra 
When I owned a Ford Dealership we built a Ram Cobra (the only replica to have been endorsed by Carroll Shelby) powered by a tuned 351 Ford Windsor V8. Thunderous performance and side-pipes
; eat your heart out Simon.
In a subsidiary business, we had a contract with the NHS servicing and repairing AC Invalid Carriages, so the Cobra sported genuine AC badges from a genuine AC, even if it was from a three-wheeler AC.
I am a big fan of trying different 'types' of car which provided a completely unique driving experience.
So clearly everyone will have driven a convertible, being a Morgan forum, I'd also recommend an SUV and a micro-car.
I can thoroughly recommend owning an Smart ForTwo, they are completely unique and fun despite their compromises. I am sorely tempted to get another Brabus ForTwo since I still miss the one I used to have.
I agree with both the philosophy and the choice Steve, we also had a Brabus Smart 4/2 and really enjoyed it. However, we part-exchanged it for another micro-car, the Mitsubishi i-car. Much of the running gear is from the first Smart's and with 4-seats and 4-doors is a highly practical town car and is nippier than you would expect, helped by a proper automatic gearbox.
To get back on topic the only car that I would truly like to own before I die is a Mclaren F1, Gordon Murray wanted it to be considered the ultimate road car and imho it has never been surpassed.
