So I'm in a similar boat except I KNOW my wife won't be driving my car since she hates driving, and hates driving other peoples cars period. In that respect, I'm not paying for insurance I don't need (unless in an emergency). In your case, I would suspect if you need your wife drive it even once in a blue moon, Tesla insurance does not make sense because it will likely be higher due to the additional of spousal insurance. This is one of the ways the algorithm/efforts costs are less with Tesla than a comparable policy from another vendor. I think if you have multiple vehicles (non-Tesla's) and multiple drivers, you can probably get a better policy than Tesla all other things being equal. If I ever need my wife to drive the Tesla, I would just cancel Tesla insurance and add it back to Geico which would only take a day or 2 and easily done over the web.