Yes, there are some home made solutions.

I posted earlier this year that I made the actual bike carriers for my
Paukchen rack out of aluminium mouldings which saved me a bundle.

I also have a bush bar with integrated bike carrier. Basically it is an
adaptation of the Paulchen rack idea that bikes stand in tracks. So I had a
fold down rack with bike rails made which attaches to the bush bar. This
enables me to carry a total of six bikes (two in front and four on the
beefed up Paulchen rack with bumper support in the rear).

For the roof and the canoe I use Thule bars and their rail attachment (a
short gutter which attaches to the poptop). I reinforced the little gutters
with an aluminium plate which extends into the gutter and takes the canoe
load off the plastic roof. 

In another van (78 Bus) I have put some straight rails on the poptop which I
use to attach bars wherever I want to support the canoe.

cheers,

 
Bj�rn Ratjen

1987 Syncro Est Alia (self camperized)
1995 Passat TD
(1982 Vanagon Diesel)
1979 VW Bus (self- camperized)