I’m really happy with this one from Chase Harper for 2 yrs now. $65. Has its own mounting straps and I added a small steel cable and padlock for safety. Very water resistant and can easily be covered for a downpour. I built a simple unglued 1/2” pvc box frame inside the main compartment to keep it standing up full size when empty (and it won’t crush a load of bread) Chase Harper 4200 Hideaway Tail Trunk - Water-Resistant, Tear-Resistant, Industrial Grade Ballistic Nylon with Adjustable Bungee Mounting System for U https://www.amazon.com/dp/B000GTTXOE/ref=cm_sw_r_cp_apip_OdjHeaG9QdMVU