New ( to me) car smells of diesel :(

[Sonolanona]

Bought a Nissan Juke 1.5 dci a week ago.. 65 plate.
Thought it had a whiff of diesel as I drove away but figured it had probably been standing a while over Xmas. Filled it up, drove about 20 miles and suddenly there was an almighty stink in the cabin. Got home. Thought I'd blast it up the motorway incase the DPF needed regenerating... seemed better.
BUT a week in there is a smell when you get in, and today driving to Ikea about 35 miles away there was a sudden stink again.
It was a from a used dealer I've bought from before with no problems, so I will be ringing them on monday and going back.

My question is: would you let them have it and see what needs fixing? Or would you ask for a refund. I'm a little anxious as my DD is expecting baby no 2 any day (she's 38 weeks pregnant) and I am likely to be the one taking her to hospital 45mins away when she goes into labour... I do not want a possibly dodgy car!

Can I insist on a refund?

Wasn’t the smell there when you test drove it? To be honest I’d ask for a refund and go elsewhere - typically they’ll take it back within 28 days, no questions asked.

My DH test drove it as I wasn't available! Usually I do a long test drive, but with a baby imminent we wanted a second car asap (DH is often away so can't rely on his being around when needed!) I don't think dh has a sense of smell!!!!
I drove it with my DD yesterday and she picked it up straight away as being pregnant she has a great sense of smell at the moment!

I just don't want them to insist on taking it away to 'check it' They were great with my last car, no issues at all but they don't have anything else suitable for me there either so I'd really prefer a refund and I'll hire a car for a couple of weeks if needed! I'm granny care for her toddler too and while I won't have him quite as often while she's on mat leave, I don't want him exposed to it either!

I would get a refund. This could be anything and I'd not want the hassle of sorting it out.