We have a V reg Mondeo estate, and when DS was tiny we had a Graco infant carrier and base which fit in the car, but was too upright - his head kept flopping forward.
The seats on the Mondeo sloped backwards more than some other cars and I don't think this helped.
I want to get a new infant carrier for DS2 who is due in October - the car doesn't have Isofix.
I will get any carseat professionally fitted to the car, but it's not so easy to know if the baby will be comfortable or not.
If you have a Mondeo, what infant carrier works for you, and your LO?