rooftop tent and double kayak

what about something like this?

http://www.ebay.com.au/itm/Kayak-Canoe-Surf-Board-L-Style-Roof-Rack-Aluminium-Black-Carrier-Storage-/321221222429?pt=AU_Sport_Boating_Water_Sports_Watercraft&hash=item4aca46e01d#ht_4248wt_1399

Have a look at a thule hullavator(?). It loads from 3/4 up the side of your car then you push the whole show up - makes no sense without pictures......
Anyway, that's about the only proprietary system I know of that will swing your yak out of the way (somewhat) without undoing it.
I have to take mine down manually each time.

Thanks for the replies I think I may have to just strap it on top with some foam blocks as there is very little room on the roof rack left and I will just keep on looking for an idea as it will be a pain taking it off to set up the roof top tent we only use the roof top tent when the going gets too rough for the caravan so it will not be too often
Cheers Steve