I want a spare. The drill on using the compressor/fixleak setup is intimidating. But I'm not sure I have this right...I should try to get the tray but not the wheel or tire, and then get a wheel and tire at the junkyard? And I assume we're talking donut spares, not real tires? I have a separate set of studs for winter, so I could use one of those as a spare if it would fit in the tray, etc. What is the best plan of action?