The Twingo was very polarising at Renault in its day. It was a fresh air through the make's boring boxy designs of the day and it can be had with a fully opening roof (not a convertible).
They may well give off the same vibe in 20 years as the 2cv does today. A more modern body and suspension with a happy face but less impressive history. They are not considered memorable today but I wouldn't mind seeing them around on oldtimer shows.
Given the tiny engine, I suspect fuel consumption will be ok and it may thus be converted a few years down the line when it is cheaper.
I think that the panther body ford/mercury/Lincoln could become more desirable in the future. They're the last body on frame American v8 cars. They're seen as a disposable car. It's popular to frame swap onto an f100 and use them for demolition derbies. They'll become exceedingly rare in the next ten years. There's a special model called the mercury marauder.