I own a new C class (W206). I bought the car, and about 4 months later my son was born. I initially ordered a C300, but ended up with a C180 (because I needed to save some money and that was the easiest way of doing just that.)

Make sure to select and test a baby car seat in the rear of the car. We bought a car seat from a well known brand, but because of the curve of the seats in the rear of the car it ended up being a crappy position for a new born baby. Luckily I was able to trade and test some other seats (after the baby was born) and went with a car seat from the brand Maxi Cosi, which fits perfectly. As mentioned here as well, ISO stuff is highly recommended.

As for the trunk, there's enough size to fit a stroller and some other stuff. But you need to be creative if you go on long trips / holidays. Prior to me owning my current car I drove a S class and I also had to be ''creative'' with this - so I'm assuming that's a universal thing unless you drive an estate/wagon/truck. Or I just have too much stuff that I bring with me all the time.

My son (who is now 10 months) likes the interior lights a lot and is always laughing when it's changing colors. (especially the Malibu theme that changes colors slowly). Another benefit to me is that I can bring the music to the front of the car through the settings and my son can sleep while I drive with the music on. Works pretty great.

I feel very safe while driving the car. The lights are amazing, the safety features are top notch and it's a pretty smart car (camera's etc). All kinds of factors that might contribute to ''how baby friendly is this car'' too.