My daughter in law put a deposit down on a car which she had seen and then changed her mind. It was a diesel and she is a low mileage driver so it wasn’t suitable, She had established before putting it down that it was refundable. She got it back without an issue. I don’t understand this but it happened.

I think the OP will be covered by distance selling regs as has already been suggested.

Moral of both stories:

1. Always do a decent amount of research first after coming up with a list of 'red line' criteria but be realistic with them - it is highly likely that no car will fit your needs perfectly.

2. For the less mechanically-minded, get help from trusted friends/family/colleagues who are to guide you on the research and search;

3. Never, ever put a deposit down unless the car meets all your red line criteria and you can affor to buy/finance and run it (all associated costs) over the time you believe you'll own it - including wear and tear repairs, tyres, etc - not just fuel, VED and insurance.

4. Always include a decent margin for payment of unforseen bills and above (current) inflation price rises in certain costs when considering the longer term cost of ownership. Many people who move jobs a lot often do not factor in changes in location to the insurance and fuel/servicing costs where they can significantly increase them.

5. Never buy a second hand car you've not checked out personally (or had someone who knows how to spot problems with them to help) and driven (for a reasonable test drive) first. Even with new cars, you always need to check them out for comfort, space, ergonomics and the driving experience before committing.

6. As you say, check to see what Ts and Cs come with the purchase and deposit. The OPs large deposit was unusual, as it sounds like a second-hand car.

Admitedly I bough my new car (via Motorpoint) 15-16 years ago, but I only paid a £250 deposit for mine (credit card) for a car costing £10k. £1k for a second hand one sounds pretty steep to me. Maybe that's the current market?

Most of the time, a deposit isn't refunable, but sometimes can be transferrable - not so bad if you change you mind on a new car and just want something different from the same make, not so good when buying second hand from an all-makes indie seller.