I work in the industry, for a manuafacturer, running the customer relations dept, so this is an area I deal with daily.
How old is the car and how may miles has it covered?
The sale of goods act is aimed principaly at the sale of NEW goods. If it is used goods then the test of reasonableness would be used in court for the condition of the vehcile based on the above. ie is it reasonable that at this age and mileage these parts are worn to this extent.
Despite what some might say the magic sale of goods act isn’t as clear cut as it would seem.
Sorry to say (and I don’t often agree with them) but I think the advice from consumer direct is correct.