The vast majority of European countries at least [0]. Every car needs to have one, their contents is standardised and since they're produced in huge quantities, they're hilariously cheap.

First aid training and an exam are also mandatory for getting your driver's license in many countries.

[0] https://www.oponeo.co.uk/blog/mandatory-equipment-for-vehicl...

In many of them: [0]

> In the following countries it is compulsory to carry a first aid kit in your car:

> Albania, Armenia, Austria, Azerbaijan, Belarus, Belgium (locally registered vehicles only), Bosnia & Herzegovina, Bulgaria, Croatia, Czech Republic, Estonia (company cars only), Georgia, Germany (locally registered vehicles only), Greece, Hungary, Latvia, Lithuania, Macedonia, Moldova, Montenegro, Romania, Russia, Serbia, Slovakia, Turkey, Ukraine

Check out the link, it also has color coded maps for first aid kit, fire extinguishers and high-vis jacket requirements.

The first aid kit also usually means required first aid training as part of getting a driver's license. However I don't know if any countries require refresh sessions, so most people probably forget all except the basics.

[0]: https://www.safetyfirstaid.co.uk/what-do-i-need-for-driving-...

In Poland you have to carry a first aid kit in your car(and actually know how to use it, it's part of mandatory driver training).

All countries with adequate workspace safety laws. It's also the case in USA.