thank you girls.
yesterday i took some measurements and looks like with the bikes angled at about 45 degrees, like someone suggested earlier, they can actually fit even in a medium size car, which will work best for me here in europe.
here's the link where you can buy a fork mount, and build very easily your own internal-car-bike-carrier.
http://cgi.ebay.com/New-fork-mount-b...3A1%7C294%3A50
thanks to all for precious feedback!
now i'm on to the "appropriate" car search
:-)