I think we had a Maxi-cosi when ours was little - what ever had the best rating on Which - they do quite extensive testing. Now he is 4 he goes in the front of the 182 and can do his own belt up, climb in so has made life much easier - I forget what brand he has now but again its one from the Which recommended list.
I think the ones with the swivel bases are great for larger cars but I don't think they would work well in the back of the 182, plus if your anything like us you will want to swap seats between cars fairly often and the bigger/heavier they are the more annoying it is with a 3dr.
I never had any issues at all putting him in the back when young I would often just get in the back with him to sort belts out etc then sqeeze out, but I'm only 5'7 so it wouldn't be near so easy if I was a proper sized adult.
We have a big comfy Lexus for mother duties, but his favorite by a long shot is the Clio... because he can sit in the front, which is good fun as they get older. Fucker complains about my driving now, told me his mummy was a much smoother driver the other day, bugger.