None, make them work for their own. And before you say, but they're good kids, worked hard, idc. I bought my own car, same with my wife, and we both agree that we appreciated our vehicles more.
I see my sister in law who got things handed to her "because shes worked hard in school and was a good kid". Well now she expects things to be handed to her. It was unbelievable hearing her complain that her sister (30s) got a new laptop from her parents recently and she didn't. Blows my mind considering she's married with 3 kids and is in her late 20s.
Parents paid for her 6 figure college degree too, only for her to literally never work. All 2 sisters did the same.
Of course all kids are different and it's your money. I would get twin M the Toyota and twin G a Toyota or Honda. Heck get them the exact same car down to the color so they can't complain or fault you.
As some one who has had multiple Vw and Audi's I would steer clear. Seems like its always a 2k repair for this or that. I have multiple f150s currently. They are decent trucks but rust quickly, if that's of concern. The Toyota will get better gas mileage I would assume and is better looking truck. My 150s get about 16-20mpg with the small engines.