First of all, I have a 2000 Honda Accord, and the stroller fits into my trunk fine. In fact, I think it barely takes up any more room than the Cortina single stroller that I had. Anyway, if you're worried, test the stroller at Babies 'R' Us, then buy it for cheaper on Amazon. I have no problem fitting the stroller in my trunk, along with $100-150 worth of grocery bags.
I will also attest to the durability of the stroller itself. While I haven't had it very long, it's already taken a lot of abuse and still looks brand new. It maneuvers well (for a double), and seems to handle additional weight (i.e. diaper bags, shopping bags, etc) very well. It was also very easy to assemble (it came 95% assembled).
Cons...
I have a VERY energetic 2.5 year old boy, and consequently, he has to ride in the back of the stroller in order to be contained. Let me elaborate. The front seat of the stroller has a detachable bar in place of a tray as the only thing (other than the harness seat belt, which is a pain) keeping the child in the seat. And, I found that in order to properly get the stroller folded up and into the trunk of my car, I have to remove this bar every time. I don't have time for that, so the bar is in a storage closet. My 2.5 year old son is also tall for his age, so the few times he was allowed to sit in the front seat, his legs stuck out and bumped into stuff as we were moving. The cupholder(s) also had to be removed for me to properly fold up the stroller, so I never used that/those either.
The lack of a tray for either passenger is a bigger deal than I thought it would be, due to lack of space. When my older son is sitting in the back of the stroller, there is NO ADDITIONAL SPACE between him and my younger son (3 months old) in the baby carrier. So, my older son sets his snack on top of his brother... and is tempted to play with/bother his brother as well. And, if he is not buckled in, my older son can climb down into the storage compartment under the stroller, since the back seat's foot rest opens out into the storage basket. Another problem is that if a baby carrier is in the back of the stroller, than the front seat does not recline AT ALL.
I agree with everyone who commented on the visors/sun shades and how ridiculous they are. I don't ever use the one for the front seat because I couldn't even tell that it did anything. The one in the back seat pops off ALL THE TIME. If I didn't need it to help shield my infant from sun, I'd get rid of it altogether.
I'm sure that Chicco wasn't lying when they claimed that this stroller is "15% lighter than other double strollers", but that 15% doesn't really make a difference. Heavy is heavy.
I did notice something Chicco improved. I have a Cortina from 2008, and I have always hated being unable to access the storage basket when the stroller is in the fully-reclined position, which it must be in order to put a carrier in it. This was a poor design, people complained, and Chicco listened. With the double stroller, this is no longer a problem; if the back seat is fully-reclined, you can still access the storage compartment via two zippers that when unzipped, create a little door to access the storage basket. Hopefully Chicco will listen to the common complaints with this double stroller, and improve its design as well.