In my opinion, if you have an opportunity to add a second unit to your property in CA, where property values and rents are on the rapid incline the long run ROI from the ADU in CA will likely out pace those of properties outside of CA.

That works for now, but we are looking to expand much more rapidly than 1 property a year. 

Notices of default are down and new construction is picking up at a rapid pace, especially in the multi-family arena.

Either go all-in like Brandon suggests - 100% business use and super depreciate your already rapidly depreciating hunk of metal to help offset the awesome income otherwise being generated from your business - or drive the cheapest vehicle that will get the job done and track your mileage.  

One word of caution, don't take a first job that is oriented around construction or construction management, I have found it very hard for folks to move from construction to development without some loss of career traction to do so.For example, I come from a family of real estate developers, but I was ambitious to learn rapidly and work for others in the multi-family development domain, so I obtained my first job (asst. project manager) for a division of KB Home (Kaufman and Broad Multi-Housing) that developed in-house apartment projects.

Bought in a growing area where the real estate market was rapidly rising.

Now if I am able to use Private Money and scale more rapidly, I have room to give the PML a decent deal.

Take note of any potential red flags such as high vacancy rates or rapidly declining rental rates.

Cap rates tend to have a narrower range than interest rates, particularly over the short term.While cap rates and interest rates are loosely correlated, and rapidly rising interest rates would generally imply upward pressure on cap rates, the change in cap rates would typically be mitigated by rent growth prospects.Good luck!

Since you have about a week, I would send an additional notice to the Westcor via their email claims box reenforcing the urgency of a rapid decision.