Finally, I spotted this product (the Koomus CD-Air Pro) and figured it was the best of both worlds: a secure CD slot mount like the CD-

Like most new cars, the CD slot has a curve to the front - the prongs that go into the slot aren’t long enough, so only the middle one goes in, which means it’s got no stability

My vents are not at good locations for the phone but the cd slot which I never use for cd's anymore, was perfect