I'd like to see the smaller gag turbines from the X-Jet and the VLJs put into a new avrocar--with fly-by-wire and steering jets.
The avrocar could have been a hovercraft had they thought to put a skirt on it.
The problem with hovercraft is that they can't turn like cars can. Having steering jets would improve things a bit.
Nothing that would be allowed on roads, though.