My new stereo doesn't have a spot for the vss speed wire, what do i do?

There should be two wire harness connectors and an antenna cable that eas connected to the 'factory' unit .. Since the radio doesn't need to know how fast the vehicle is traveling - it does not need a vss signal. Perhaps you have mistakenly identified this mystery wire as a vehicle speed sensor wire. Test replacement radio to see if everything performs as it should.. Its a pretty simple unit to R&R ..

I would recommend reaching out to the aftermarket stereo seller for installation guidance. I can tell you that the VSS wire is used specifically for the functionality of the stock radio that raises and lowers the volume dependent on vehicle speed to compensate for road noise. It is doubtful your replacement audio unit has this feature.