Do these bikes have anything other than the seat to hold the batter in place? I have a 2006 that I bought a few months back and it came with no strap or tie down for the battery. Just curious if I am missing anything.
That's it, the seat holds it down. Has worked for me for 12 years and 160k miles on 2 GS500s.
If you're concerned about it, jam a small piece of foam between the battery and the steel frame towards the back of the bike (see pic). Or use a small wedge - like soft plastic doorstop wedges you get from a $2 Shop.
(http://lh5.ggpht.com/_AYmU9ozxu_o/TS9pf4w-E3I/AAAAAAAAAgg/WfHc7Fm-xRM/GS500Battery.jpg)
Michael