ok, I'm surprised that Wouter didn't say this so I will - look at an F-16. A used Taipan 4.9 or nice new Blade.

Heavier than the A for sure, but not near as heavy as other boats. I don't think the mast is as tall as the A, but you also get rig configuration changes that will satisfy just about every way you might want to sail (one up, two up, sloop, uni, spin...). If you want to tame it down for the kids to sail on their own have a sail maker build a smaller main for you. Not as rough and tumble as a Hobie can be treated, but maybe a little more so than an A. I'm sure a late night session with a couple of beers and you can engineer a set up to get it on top of the car without dropping your nuts on the parking lot.

The first time you have it yourself with the spin set smokin' downwind you'll be happy you made the choice.

If I were in your shoes this is the option I'd try very hard to make work.