I built a bike rack from mine from PVC pipe.
Make your own Bike Rack
The one shown here is for 3 bikes, I built mine for 4 bikes. Just measure first to see how much space you have. Leave enough space on each side for the handlebars.
One thing I would mention is I put mine all together first then glued it at the joints (exterior) without taking any joints apart. There are so many tees and 90's if you glue it inside the pieces and get one piece out of alignment, you get to trash the whole thing and buy new tees and 90's and start all over. The glue is unforgiving, there is no adjusting after the fact.
I've used mine for over a year, works great.