Female, JD/MBA (lawyer/finance), now a math and physics teacher (early "retirement" gig)The thread linked previously above helps a lot as any financial output is only as good as the inputs Good to know your education background (I'm a licensed CPA) as unfortunately a lot of people come onto forums like these talking finance with quite literally zero financial skills so it's hard to know who you are talking to a lot of times. Glad to know you've done some real number crunching already!
I think I must still be missing something though.
If your $1,633 a month for the MYP is a fixed cost with no maintenance or charging expenses and you can get a new one every 12k miles, why would you be concerned with battery degradation? And why would you want or even need another vehicle?
There is no financial savings in owning/leasing 2 vehicles over 1 vehicle. In fact you have to pay $1,633 every month regardless of how much or how little you use the MYP. So I'm not sure how buying another vehicle (M3 RWD) to keep wear and tear off a vehicle you don't own (MYP) makes sense.
If the discussion is "keep my corporate fleet MYP" OR "buy a new M3 RWD", well that is an entirely separate cost benefit analysis which based on how much you drive could still lean in favor of the MYP.
I would be concerned about battery degradation if I bought the MYP instead of doing this monthly payment fleet situation. I have been able to see the effect on the battery of my heavy useage without having to own the specific car. Initially, I had a MYP on order, but I waited too long and lost the order (my fault, waiting on 4680 and a nonexistent tax credit). My plan was to drive it 15k/yr. I can see now that I would drive it like my Prius, and would have 50k vs 15k miles per year. I like it too much!
I would have a $850 payment (assuming $7000 tax and downpayment) for the M3 RWD. Tires are less expensive and I would mostly charge at home. I would prefer a M3 LR (or a MYP), but I would be buying it for the LFP battery and trying a "running it into the ground" experiment. I could write them a check, but I'm putting the finance numbers to compare this to what I currently have.
If I did this, I would get the MYP for two months a year, not 12 (for the summer).
OR, I keep on paying $1600 monthly for a MYP. I can afford it, but it seems crazy paying 20k a year to do this, when I could pay $47k for a Tesla to run into the ground where the break even is a little over two years and it should last theoretically much longer because of the LFP.