re: If an employer pays full mileage rate, does leasing make sense?

I don't understand where the $20k down payment is coming from. Is it just a personal choice or does MB require that much down? Also don't understand how you estimate 75%-100% return as "reasonable" over a 4 year period. That seems aggressive. And since when do you get to write-off a car lease on a personal vehicle?

I see it like this - option A is cash flow friendly, with employer reimbursements covering the lease. At the end of the 3 year term though you're stuck with no car.

With option B, assuming little to no down payment, You and your wife pay $17k for a car with a ~$30k value after 3-4 years, and its yours to keep. Or if you chose to sell it or trade it in you effectively realize those gains, $13k, tax free.