In my case, the possibility of having the advanced sound system was not an option in october. When the car was build (mid-october), even if on the website it showed "Advanced sound system 400$", it wasn't available.
So they're giving me the basic sound system.
I'm a huge fan of listening music with great sound, so I wasn't even satisfied at 100% when I heard the Burmester back in May. I'm paying an extra 3500$ and Mercedes will send my car to an "audio shop" and they will replace the speakers, add an amp and 2 subwoofers.
I'm crossing my fingers that this won't do any "error message" in the system, because I know that sometimes when you change a little thing in modern cars, you can get some trouble. But the fact than it's Mercedes that is taking care of sending it at the audio shop and when I'll get my car it will be already installed, I think it's something really positive. Maybe the sound system is 2500$ et they're taking 1000$ of profit, but I don't care : I prefer that everything stays with the Mercedes warranty.
Also, I heard that a few CLA have some pieces that "rackle", I don't know the word in english but it's some parts (like door panels) that isn't fixed very well, and make some sound (vibration) when you're driving. Make sure when you go search your car at MB that everything's fine. I think I'll spend 2 hours minimum to check everything's clean haha!
Anyway, these type of problem is covered with warranty, it's just not really cool to have to go back at MB after buying a brand new car, with over 8-10 months of waiting.
I Already bought the panamericana grill (like your CLA45) since this summer. I love that grill. It's unique to AMG and I will replace it (mine is a CLA35), I really think that change the look of the whole front of the car.