: I have a subaru Imprezza sedan fitted with roof racks. The racks are 32
: inches wide with a spacing of 24 inches.

Get a pair of uprights from your local kayak retailer (they're about
25 quid in the UK, say $35 ?) Then you can have the kayaks on their
sides. That should easily get you two on top.

I substituted some wider bars (its just square steel tube covered in
PVC, with some slots cut in to take the widgets that attach to the
roof bars). The car is wider at ankle height than at the roof, so the
new bars don't overhang, but I can readily get four sea kayaks on top.

The car is a Subaru Legacy estate. My wife has an Imprezza saloon, and
we get three sea kayaks on that with the standard roofrack. Tie the ends
of the kayaks to the ends of the roof bars to stop potential mishaps if
the canoe straps in the middle should slacken. I have no bother driving
the full load at up to 90 mph (about the most you can get away with on
British roads nowadays), though the speed is limited if there is much
of a cross-wind, and fuel consumption suffers if you keep that up for
anything other than overtaking :-)

Here is a (not very good) photo of four sea kayaks and a white water
boat on top (and the caravan we towed in the background). The fifth
(plastic) kayak on top was a bit difficult, but quite secure enough
to drive a couple of hundred miles to the Holyhead ferry (all motorway
speeds) then across Ireland (and back the same way), and we probably did
a few hundred miles with the kayaks on top but towing nothing too. There
is just one pair of uprights, between the two fibreglass kayaks (the two
on the left). You can see that there is still plenty of roofbar sticking
out at the right - if I'd made the bars just a little longer I'd get five
on side by side, as some friends did last year to drive to Croatia (about
1600 miles each way, over the alps). You can't have too many boats ;-)

Andy