This topic has been discussed extensively on this forum. Here are some links:There actually is a spot where you could mount one and a GM spare tire kit but it eats up a ton of the cargo space.
The bolt is screwed into the car structure, and hold the wheel down securely. The rubber straps are designed to stretch and will have more potential points of failure from snapping to the S hook hole breaking to the S hook straightening out. This would not be a concern of mine in normal use. but in a violent crash inertia takes over and thing in motion tend to want to remain in motion. IOW, the tire will want to fly. Whether it would, I don't know. There is also the side impact force that will want to shear the tire to the side. Just saying it is a concern.Not sure that a single bolt would offer much better resistance in a crash.
It looks like there might be a little space beside the muffler, but we'd need heavy structures added to hold it and then shield the gas tank from a rear impact. (It's just on the other side of the rear tires.) All that weight would be a killer for this car.Since the Volt has a high rear ,has anyone tried a trough -bolt with the tire outside the car frame?. Seems shoud be enough hight at least for a donut tire, just like the old trucks, preserving storage room in the back.
I like this solution. What size is your sonic wheel 16x6.5 or 16x7?I opted for an "in-between" approach: a slightly smaller "full-size" spare on a 16" Sonic wheel with a tire size of 195/45R16. The diameter is slightly more than the donut spare, and the tire/wheel combo with spare tire cover will fit, strapped to the back of the larger rear seat back, allowing it to sit upright most of the time, consuming less space, and folding with the seat when necessary. The tire is rated at 1100 lbs. carrying capacity, works fine when mounted on front or rear, and can be used for any distance necessary, since it is a regular tire. The photo showing 3 tires: largest is current stock Volt 215/70R17, 195/45R16 on Sonic 16" wheel, and a donut spare from my wife's 2008 Malibu (slightly larger than Cruze/Sonic 16" donut). The standard size Volt 215/70R17 tire and wheel are wider than the larger seatback; would not allow seatback to fold. Bought a spare tire cover from an auto store, stretched the standard cover over it. Every attempt to utilize a spare tire creates some problems; this solution has worked very well for me.