Having a parking spot is a fantastic bonus, and being pet friendly will open up your space to many more renters too.

-Are you open to a bonus/penalty system, for the overall occupancy and financial performance of the property?

be careful of those offering to do these deals and wanting commitment money up front 95% of those will be fakes and will just steal your money.. you have to realize that gap funding behind HML is by far the most risky loan anyone can make in real estate .. so u may not have many if any takers on this unless your offering a big equity upside bonus and more of a partnership.

I bought mine because it was cool and cheap, the in garage deliveries were just a bonus. 

Lots of bonus depreciation opportunity.

Do a cost seg study and take bonus depreciation to offset other income.

Read the book "Long Distance Real Estate Investing" by David Greene, then decide if you would like to sign up for an investor academy (which will probably cost hundreds/thousands). 

Bonus question: what kind of impact does this have on my taxes and how do I file this?

In addition to what was said above, for the software that has a free trial option, sign up for it and use the software for a day (or at least a few hours) as if you are using it for real, then call their customer support too and get a feel for that. 

Bonus depreciate it at 60% minus 25% for the land.