Bought a pair of Baja Rack 5 gallon Gas Can holders recently when an online reseller was having a inventory reduction sale. Each holder accommodates 2x 5 gallon gas cans (either Blitz or Nato cans) but was designed for the Baja brand rack.

Luckily to fit my rack, required a very simple mod. Drill 1 new hole and buy 1/4" longer 5/16" dia. bolts. Instead of the original zinc coated bolts, I opted for galvanized bolts & washers although I did use use their zinc plated nylocks.

After drilling a new 3/8" hole to relocate the mounting plates so they could grip my rack, I simply primed and painted them black to match the original paint, then mounted it all up.

Here are some pics I took. Sorry, it was late when I finished. I'll take better pics of the mount in the next day or so for those looking for a similar way to hold their gas cans. While your roof rack may not be identical to mine, you can likely mount the holders the same way.