Engine size 698cc turbo
Size 3427mm x 1615mm
Used price range 4200-10,800
Smart's interpretation of a Kei convertible came after the company's success with the original Smart car. Unfortunately, making the Roadster, and its sister model the Coupe, wasn't profitable enough so production was stopped.
The Roadster is more common on the used market but, due to its popularity, costs more than the Coupe. Cars at franchised dealers are expensive compared with those at the independent specialists that have sprung up in recent years, but getting parts isn't too much of a problem.
Or what about
Produced between '01-'05
Engine size 1600-1800cc
Size 3975mm x 1680mm
Used price range 2500-8000
Okay, this is technically cheating because it's bigger than all of the other cars we've looked at, but the Mazda makes a great alternative. Not only are there hundreds for sale at any one time, but it's reliable and easy to maintain, too. It will cost you more in fuel than traditional Kei cars, but then it's better to drive and much more practical.
There is an earlier MX-5, but this generation of car is a better bet as it is younger, but still good value. The 1.6-litre model is the economical choice, but the 1.8-litre has enough punch to make driving really fun.