My partner is an awful driver

I love them, but god damn they just have no awareness on the road.

Constantly accelerating then braking, a red light will appear ahead and they will still be accelerating and then brake heavily later

Drives past some cows or horses and slams on the brakes to slow down and have a look, without checking if there are any cars behind them

Has their German shepherd sit on the front passenger seat unrestrained while they drive, I’ve tried telling them how dangerous it is for them and the dog

Will tailgate cars and motorbikes and play on their phone. I called them out on this saying that if the motorbike has to slow down quickly and you aren’t watching it will probably be a fatality.

They complain that everyone around them is an awful driver and has no clue, but they have been in 2 small accidents of their own fault in the past few years we’ve been together

I’ve politely offered some tips, especially if they are driving my car but they get super defensive and says that they are a great driver and that if I have a problem I can just drive us everywhere in the future, they are so defensive over it one time they stopped in the middle of the main road and said that I can drive or we aren’t going anywhere.

Has anyone handled this situation before?