What you are asking about, the car insurance, the useage, you paying all the money - I like how you now see it has no point when asking him for the car. Those discussions and arrangements need to be made before, long before.
This is part of that see a lawyer, know your rights, know what you need, want, are willing to give up, and what you will fight to the death over. Where the car, its finances, the use - all end up on this spectrum is up to you. That gift of time you have, use it to figure out this stuff, before it is too late. Having your ducks in a row will be so very helpful.
Anyhow, the car to me is more of a boundary issue and a bullying issue.
You pay all the costs for the car, and can’t use it when you want or need to. Screw that! Maybe you use your car, and you share it with him - not the other way around. It would be nice if you both could share it, however that isn’t going so well.
My previous advice on asking is for the current arrangement, and to keep Gerda’s head from exploding from stress - again due to the current arrangements.
Decide if, and then what, changes you want - then make them. Get some boundaries on his antics. H, I will be using the car this Friday. That’s it, no further discussion. Let him get mad, leave the room. He writes another long crazy email, read it, save it for your L, don’t answer him, and use the car. Tell him the boundary regarding his bullying emails. (You’re right this is not just about the car)
This course of action is again for Gerda. You are walking on egg shells and don’t need to be bullied. Yes, we do put up with some less desirable and really disrespectful behaviour, it is up to you how much you are willing to put up with.
Gerda, you really made me sit back and take notice when you told me of how you remembered when I told you to let go of your fear. A little tiny DnJ sitting on your mantle, I was touched. It meant a lot to me. I do consider the affect of my words and the serious inplications and consequences that they may cause.
You know I like and care about you and your kids. So I am sure you realize where I am coming from and whose interests I am concerned about. Egg shells hurt your feet, and pretzeling yourself will only get you a bad back.
Let go of your fear. Do what is best for Gerda.
I am here for you.
I will support you.
Hey you, the bullying talkative guy - That’s not fair!
DnJ
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.