Thanks for that. Like @Glos Guy says, MB will always try and sell their cars for the maximum they can get. They’re willing to cover the insurance, maintenance, etc, so that at the end of the lease, they have a car they can sell for a profit. That’s how they come out ahead.
If I may, you say your son-in-law is going to be doing more of the driving from now on? I know you said you like the Rav4 but maybe this is an opportunity to consider a car just for you and your wife?
If it were me, I’d inquire into the potential cost of the Rav4 but unless they offer a really reasonable price, I’d walk away. You could go to Toyota, buy another Rav4, that way you have a direct link to the dealer who sells you the car. You’d be buying peace of mind and protection should something go wrong.