I would think loading the Harley first off to one side and toward the front of a 12ft garage the OP could back in the spyder at a bit of an angle and be fine and with room to spare. On the orig ques the OP asked, what I try and watch for in a purchase is can I get into the M bedroom without running slides out, can I load frig or get to stuff to make a sandwich without running slides out, I like frig on curb side of RV so if I need to run slide out to load, slides not sticking out into traffic. I also want main bath on street side so I have access at all times to bedroom. Does it have OSB plugs throughout for phone charging, does it have cabinets that we can reach for things like plates and glasses, these are just a few things I look at due to having to load hauler while parked on a street and we stop in rest areas to rest and don't want to run slide out to get to bedroom and take the chance of a semi hitting us. But as I mentioned if you get one with a closed 12ft garage you should be fine storing both your Harley and spyder at the same time. These things are what I need but may not be important for others.