My H has just done similar.
Except we don't have an understanding that his bonus is for him - the way we have operated over the years is that it is family money.
Yet this year, he has seen fit to wander off, no discussion, and spend stupid amounts of money on a car. We already have 2 (pretty new) cars, which would generally be seen as luxury cars. One of those chosen for family practicalities ('my car', nothing wrong with it but purely chosen for car seat arrangement ease/school bag/musical instrument ferrying etc) and one chosen (despite not being quite as practical) because it was what H 'wanted' (so he already gets a 'better' choice of car because family needs are already catered for - H commutes to work on the train, and walks to the station so no need for him to have free choice on a car).
Anyway, H waltzes in and announces his purchase. There are so many things we could have spent that money on - family stuff, things to make our lives infinitely easier (we have 3 disabled dc), but no discussion, it's done. No way I have the opportunity to spend even a fraction of that money on something just for me.
And crowning glory? I'm not allowed near it. Hasn't insured me (im the better driver, which he would admit too) and hasn't even given me the spare key/let me know where it is.
So his car sits on the drive all day (in the way - we now cannot fit his other car on the drive, and we have restricted parking where we live meaning I have to move it about constantly to avoid fines) while he swans off to work, and I cannot even move it if needed (frequently - we have major building works going on and the builders often need access to the drive), which quite frankly is downright embarrassing - the builders ask me to move the car and I have to say 'oh, that's H's car, I can't move it I don't have a key' - cue knowing grins and the odd bit of banter about him not letting me drive his car etc.
Pathetic, tbh.
I tackled him about it (have no desire to drive the thing daily, but having the spare key to move it around would be handy) and apparently I would need to be taught how to drive it as it isn't 'intuitive' whatever the fuck that is supposed to mean. I've been D driving over 20 years, several different cars of all sizes; both automatic and manual. Never an issue. And now I need to be taught how to move one off my own driveway? Fuck that.
Seriously pathetic.