How does tax exemption on EV Lease in Washington state Work?

Anyone know how the sales tax exemption on EV leases in Washington state works. The dealer has no clue about it,

Is it still available (best i can tell it is through this summer)?
If the MSRP of the car is >$50K but the purchase price/ capitalized cost is less than the 45K threshold does it still apply - or does the MSRP have to be below 45K?
What do I (or the dealer) need to do to get the sales tax waived since they don’t believe it exists?

Thanks!

WA DOR is not very clear on the guidelines. Information I found while trying to get a tax exemption myself:

I believe it should be MSRP, but probably the safest option is to make sure the Gross Capitalized Cost is below $45000.

Also, my suggestion would be to find a dealer who knows about the sales tax exemption. I unfortunately leased my car through one that had no clue and am currently in a protracted battle with the DOR trying to get my taxes reimbursed.