...simply tint the front windows to the shade of the rear ones (night pkg.) provided my dealership allows this, given it will be leased. That's it. The premium package includes the HK sound system which I love. The engine and suspension set-up on the 45 needs no mods. Maybe a vanity plate that hates on the wannabe competition?
The dealer is installing tint on the front windows to match the back one like scott wants, plus they are adding 5% tint to the sunroof to keep the car cooler. I might consider a chip/programmer but not in any hurry to mod the car...yet.
I'm going for the tints as well when I get my cla, maybe lighter shade though. Will put nice VIP rims on those when threads of tires wears out. Won't do any performance upgrades for now. I know for sure I will be getting the spoiler and the rear stainless handle option, I know not everyone likes it, but it hits the spot for me. Will definitely put a small subwoofer (amplified) in there just to help the HK's a bit, probably a 10inch sub in the trunk since we have plenty of space in there.