Why have a spare if it isn't kept with the vehicle it fits?
I you have to remember to pick up the spare from the garage every time you go somewhere, you will forget it that one time you really need it, guaranteed.
I had read somewhere that it's not a good idea to store tires close to electric motors. Something about gasses (ozone??) given off from a running motor can eventually cause damage to the rubber.
...you could buy the premade tire holders from Tractor Supply type stores. The spare tire brackets are designed to bolt to the trailer frame...
