After some advice regarding a used car purchase.

[j.col]

My son bought a used 20 plate Merc CLA 220D 9 days ago.
He bought it on finance and paid extra for a 1 year extended warranty.

On day 5 of ownership the engine management light came on and he immediately contacted the dealer who told him to bring it in straight away.
Dealer diagnosed a faulty O2 sensor, put the car on the lift and claimed that when he checked the sensor, he felt it click into place.
The light did turn off, and after a 10 minute test drive, the engine light remained off and my son drove it home.
To be fair to the dealer, he did say that if the problem reoccurs, he will change the sensor.

Now today, the engine management light has come back on again.
He does work shifts, so it will be Wednesday before he will be able to bring it back to the garage.
The garage is 80 minutes drive away (i know this is his fault).

He is unsure how to proceed.
He doesn't want to reject the car but is starting to lose trust in it.
Am i correct that he can reject it within 14 days for any reason?
He doesn't know if its the same problem again until the car is scanned, and if it is, the dealer said that he will replace it for him.

If he does reject it, does he get a full refund, including the deposit and extended warranty?
I presume the dealer can deduct a small amount for the mileage he has added to the car?

 

[j.col]

Thanks everyone for your advice.

It turns out that the engine warning light turned itself off and he never took a photograph of it being on.
So for now he hasn't contacted the dealer as as of right now, there is nothing wrong.

He genuinely likes the car and wants to keep it, thats why he want to a dealer 80 minutes drive away.

Its not a Mercedes dealership, just a regular car dealers that specialise in prestige cars.

 

[j.col]

surely its just a generic warranty then that can be used at other vat registered garages. can he not speak to the dealer about taking it somewhere more local?

Not sure tbh, it may be worth asking though.