I'm coming late to the party, so I'm assuming others have made these same comments.
In fact, my suggestions are so dumb, I'd be disappointed if someone hasn't made them already.
Brilliant idea. BRILLIANT.
I have two suggestions to simplify the installation.
1) You could simply use a REDA gas can (they are available again). These are very tough cans made for motorcycle use.
https://www.amazon.com/REDA-Innovat...mzn1.fos.18ed3cb5-28d5-4975-8bc7-93deae8f9840
2) Simply strap the can in place with a shock cord. I just tried it out and the can is held in place very solid. This way
you don't have to make any permanent modifications to your Spyder. It's so solid, I'd have no reservation of taking this on the road.
Did I say your idea was Brilliant?