I can tell you without fear of contradiction that you DO NOT want to drive an open-wheel car in the rain.
Neat critter, though.
That concept would be good in a Lotus 49. Fit right in the engine bay, probably. Then you could drive in the rain.
Marry up the "neatness" factor of some of those old sports cars with the technology of today's engines and transmissions and you'd have something truly worthwhile.
What with everybody using wind tunnels in the sheet metal design in order to get the fuel economy, 90% of today's cars look like snot bubbles. No character.
Somebody will probably wrap some aluminum or fiberglass around that Ariel and create a pretty neat go-buggy.
, Art