I was thinking you could cut the straps off altogether and use velcro to attach it to the trans tunnel carpet (i.e., in the same spot)
First time I saw those saddle bags, I couldn't get past the buckle that will rub the paint off the silver trim and the other strap having to stuff itself under the leather e-brake boot. I use the e-brake all the time while parking off road, and that saddle bag strap will pull the e-brake boot every time.
I like the idea, but I can't handle generic things that don't really integrate that well onto the vehicle.