That always works too, and I haven't even thought about mounting the things on the KLX yet (I've only had it a few weeks), but I have one bolted to a pannier case on another bike and it works great.

In thinking about it, you could even bolt it to the front fender and I think there are a few other possibilities.

The only problem I have with mixing fuel bottles and other luggage is that the bottles are almost impossible to fill from a service station pump without blowing fuel all over the place and the last thing I want to do is put petrol in my underwear.