If it is over 30 days since purchase the seller has the right to choose whether to repair it or refund you (including deductions for use).

That is the simple fact of the matter.

On an 8 year old car you are certainly not covered for everything and anything as a great deal can be put down to interpretation as to what a "reasonable" person would expect from such a car but this sounds fairly fundamental so would think you would have a strong case.

Don't assume the seller will not be reasonable, contrary to popular opinion most are as long as the buyer is similarly reasonable.

I don't know if judge Rinder sets a legal precedent. It's a TV programme and the TV station pays any awards, not the defendant.

"I’d take the money and run."

I was thinking the same. Worth a smallish financial loss just to get rid of the worry and stress.

Grab the money and then take them to the small claims court asking for the £400? Small claims is time consuming and a pain for the dealer,

He may be prepared to pay some or all to avoid the hassle of even going to court and indeed you have a possibility to win. It is not for you to somehow accept a financial penalty as it will have another owner on the registration document. He shouldn’t have sold you a faulty car in the first place. As for selling you a warranty, they are largely useless, do not cover faults on purchase and you have six months protection under consumer law anyway.

Grab the money and then take them to the small claims court asking for the £400? Small claims is time consuming and a pain for the dealer,

He may be prepared to pay some or all to avoid the hassle of even going to court and indeed you have a possibility to win. It is not for you to somehow accept a financial penalty as it will have another owner on the registration document. He shouldn’t have sold you a faulty car in the first place. As for selling you a warranty, they are largely useless, do not cover faults on purchase and you have six months protection under consumer law anyway.

Please don't peddle the six.momh stuff. You potentially have some comeback on some cars for 6 months but on most on most things you do not. It is misleading to imply people do.

The 6-month threshold is to do with the burden of proof - up to 6-months, it's up to the seller to prove the fault didn't exist at point of sale - after 6-months, it's up to the buyer to prove it existed at point of sale - if the fault didn't exist at point of sale, but developed later, then it's down to reasonable expectation taking the age and price into consideration.

"You potentially have some comeback on some cars for 6 months but on most on most things you do not. It is misleading to imply people do."

I didn't. Having been on the seller side of the equation for some decades I am pleased to read that it protects the seller as well, that is not particularly evident from my perspective.

However I detest those dealers who knowingly sell defective vehicles, and those who don't face up to their responsibilities when they unknowingly do sell a car with a fault. Something that with the best of attention can sometimes happen.