Or... any advice on other marketplaces.

I will also check the marketplace. 

The more time you spend out in the marketplace looking the  more likely you will be to find an opportunity to do something with the little cash you have.A good place to start is Ultimate Free Beginners Guide

I see in NY you need to have a real estate license to be a PM so maybe if he got certified and got some sort of insurance this type of agreement would work possibly?

@Ahmed Nijimif they tried to call the police mostly they are not going to negotiate cash for keys deal & not willing to leave...once they recognize there is an attorney involved they might to.If I were you I would never make any contact with them in any way...get an attorney to handle it properly...here in Texas there are many rules have to follow when giving the 3-days notice to vacate...cant just stick it on the door and thats it...Imagine if there is a screen door my attorney told me have to stick it from inside facing the main entrance door besides all of that to make sure they receive the notice had to have it sent with certified mail & regular mail...not mentioing how careful to be about what to write in that letter any mistake could be used against you if they wanted to fight the eviction.Have done both eviction and cash for keys here all depends on the first impression I get from the former owners.Cash deal was accompanied with short term lease for the period I gave them to leave waving any rights they might have to fight the posession...all docs were notorized.Hope that helps*Not giving any legal advice here.

This should post be bumped to the Market Place.

I would go onto Craigslist or Facebook marketplace and search for plow services, I see them on there all winter and I am sure someone from the Portland area here on biggerpockets will have a good alternative to 8k for three car spots!

Make sure to send it certified, return receipt.However, if he did not give the post office a forwarding address either, it will end up coming back to you. 

I'm not familiar with the San Diego Marketplace.

* Are you a Certified Property Manager?