Don't want to share my car!

[McScrooge]

Been sharing my current car with my sister for a while now. It worked out well as she'd do longer distant drives for me that I couldn't do at the time and that was the agreement in turn for her using my car.

All was grand, until she started getting a bit big for her boots and expecting the car to be there everyday when she wanted it, and would kick off when I was using my car and wouldn't be at home.
She no longer does any long distance driving for me either and hasn't for about a year now mainly because I'm forcing myself to do the drives to build my confidence.

I'm getting a new car next week and she's kicked off that I haven't already stuck her on the insurance, I can't put her on the insurance until it's live and gone through on the day and didn't like the fact I told her I wanted a few days to get used to my new car by myself.

AIBU to think if she's kicking off already then I'm best not sticking her on the insurance at all?
It'll cause world war 3 but all she does is pay for petrol, she doesn't pay for anything else like MOTS, upkeep etc and drives it more than me!
I appreciate all the driving she has done for me in the past but I really just want the car for myself now and not have to worry about having to get home to avoid a kick off or have a stupid rota for using my own car or do I sound like a Scrooge?

Seriously, if any of your family give you grief, point out that not only did you pay for the car that she 'shared' you paid for the insurance, the servicing, the MOT and the maintenance. She didn't share anything other than the use of it. And only you had the inconvenience if not having your own car available when you wanted it. Oh, and remind them that she hasn't driven you anywhere for the last 12 months, so any 'deal' no longer exists.

I'd also point out they're more than welcome to share their cars with her. I'm sure they'll be falling over themselves...

A simple no is adequate. And don’t give her a key to the new car.

How’d it go @McScrooge ?

Erm why not both grow up. You grow and say hey my car get your own and that's that

She's taking the piss out of your kind nature OP. People who go into apocalyptic rages when they don't get their own way do it because they know it'll make (weak) people capitulate to their demands to keep the peace. Don't give in - especially not given that she's previously refused a similar arrangement which would benefit you.