J.D.
check out Sunshine Kids seats
My husband and I both drive small cars to save on gas and were hoping to be able to afford to get a 4 door by the time my daughter needed a convertible car seat. Well she has hit 22lbs at 7 months and we can't get a car yet. So anyone that has a two door car or a compact car that can give advice that would be greatly appreciated!
check out Sunshine Kids seats
I'm not sure how it would fit in either car, but I trust the britax marathon from tons of research and personal experience with one in a fatality accident! Babies r us will let you try some of their seats in your car and they have 20%off britax right now. Or sometimes there are really good deals at albeebaby.com or new in box on eBay, free shipping on both! Once you find one you like at bru then you can order online. Merry go round in Bellevue has a good selection too and will also let you try in your car sometimes.
The Evenflo Triumph Advance is a great seat for smaller cars. I had one for my older two son's and it was very easy to use and install. Kiddo's slept comfortably and allows for rear-facing up to 35lbs(I believe). FFing is 65lbs and should last to booster age.
We have a True Fit for our daughter now, which is also awesome but won't fit your needs. HTH!
http://www.amazon.com/Britax-E9LC22S-Frontier-Combination...
My daughter has a Britax Frontier. It has a longevity that i don't think anything else can match. (Mmm.... it might not start small enough for her - i think my daughter was 2 when we got it - ah, i see, i am answering the wrong question.)
Anyway, we have the Britax Roundabout, too, and it is decidedly awesome - better than i'd imagined in would be when i got it. But having used other borrowed seats while travelling, i am so glad we had the Roundabout!!
The Marathon, i think, lasts longer, but is not as small if you have a small car.
I'd highly recommend the Britax brand. Babies R Us has many convertible carseats and you can often take them out(the store model) and see how it fits in your car. Then shop for the seat online as you can almost always find them at a lower cost with free shipping.
The graco nautalis is also another great option. What I like about both the Britax and the Graco is that they both have "longer life" meaning that they last into higher weight limits than the normal 40lbs. I believe that Britax I have goes to 65lbs. My plan is to keep my daughter in a 5 point harness as long as possible, so this makes it easier.
I don't have a compact or two door car, what I do have is a Honda Accord with 3 car seats in the back row, so I have done a TON of research into seats. We chose the Sunshine Radian. It is a convertible seat 5-40lbs rear facing and 20-65 lbs forward facing, with the 5 pt harness and LATCH system all the way up to 65 lbs.. It has high safety marks and is the narrowest base on the market right now (so 3 in row fit nicely in my back seat). The downsides to the seat IMO are the price ($183 on Amazon right now, though can be as high as $230) and once you install the seat, you WILL NOT take it out again b/c it weighs so darn much. The seat itself weighs over 20 lbs! So if you were planning on buying one seat to switch out between your car and your husband's, this one could be a pain. Overall I recommend this seat to anyone looking for a convertible, but especially if accommodating a smaller space and a larger child.