It's tight, but possible. For the baby on the way I would tell them to get a Keyfit 30 if they want an infant seat. It's a great seat, narrow, and fits the Cobalt well. It also puzzles well with FF Radians.
We have a 2008 Cobalt and when DD2 was born DD1 was 4 and DS was 2 and still RF. I couldn't fit the Keyfit next to a RF Radian so we had this order: RF Keyfit, FF Radian, Keyfit. It was a tight fit for the driver and front passenger but DH and I are both 5'10" and we made it work. Then once DS was FF we had this order: FF Radian, Keyfit, FF Radian. When DD2 outgrew the Keyfit 30 we switched to this order: Recaro ProBooster, RF Radian, FF Radian. Honestly it's a giant PITA to buckle DD1 into the booster so if I see a good sale on a Radian XTSL I'll get one for her for this car. It just hasn't been a priority since we got our second car and the kids rarely ride in the Cobalt anymore.
I seriously recommend the Radian/Keyfit combo. What do they have for seats now? I think they would need at least one Radian and the Keyfit to make it work.