On my 1979 Accord I used to use a rectangle of heavy PVC tubing, maybe 3" diameter. I had simple metal brackets that it would fit into. These were bolted onto the top of the front bumper - lots of metal there. I used long quick pins which went through holes in the upright faces of the brackets from front to back and, on the way, through holes drilled in the bottom leg of the PVC rectangle which would hold it at roughly the correct angle (canted slightly forward) without the glider being there. Once the glider was tied on, it was pretty solid. I wouldn't have wanted to drive any distance with the rack in place and no glider on top, but it was so quick and easy to remove the rack that there would never have been a reason to do that.
The PVC is dirt cheap, easy to work with, and weatherproof. I don't know where I got the metal brackets. It's possible that my instructor at the time gave them to me. The only drawback I found was that one of the upright legs of the rectangle was directly in my forward line of sight while driving and would catch and reflect my headlights at night. On my Subaru I am now using a PVC double-T (crossed at both top and bottom) with just one upright at center. This solves the visual obstruction and headlights problems pretty well, but isn't as stiff side-to-side. Also, I'm using tie-downs to strap it to the front bumper, because there isn't enough metal there to mount hardware to.
By the way, what kind of shape is your Accord in? I have a 1982 Accord (LX hatchback) which I want to sell. The body is in pretty bad shape but it has only a little over 100k (the only previous owner was my mother) and runs well. Just passed smog test yesterday with flying colors. The battery and the tires are virtually brand new and all by themselves are almost worth any price I can reasonably ask for the car. If nothing else, it could be a parts car, for someone who has room for that, although it would be a shame to take it off the road. I'm about to put it up on Craig's List, thought I'd mention it here just in case. By the way, on this car I have been using a simple padded ladder strapped to the roof racks, with no support at the front end. Not great, but works OK. I haven't improved on this because I mainly use the Subaru to go flying, and I really never expected the Accord to keep running as long as it has.
- Matt (Santa Cruz)