Greenberg:

Regards to the AK: Install it if I were you, it makes the vehicle have a more aggressive and intimidating look. You will see several black ones with and without the AK. The AK is more noticable on other colors, especially white, which makes it look real clean and elegant, but no where near as aggressive or intimdating as a black vehicle or the darker colors.

Regards to Tint: Read post number #8.

Reagrds to the Rims: I would definitely purchase some wheels, for me I will be installing 22", you did not want to go bigger? If your going for the all BMW look and feel, go for the BMW OEM 20" or even the 21" wheels. This really depends on what look you are going for, but for me since I will be paying for a set of wheels and it would not be too far off in price with BMW OEM's, I opted for aftermarket 22" wheels.

Good luck on your decisions and do not forget to post pictures.

On my Space Grey X5, the areo kit definitely made it look more "macho" (and aggressive and intimidating :) ). I had not seen an aero kit before I picked mine at the dealer with that option. The other X5/X3's looked so normal in comparison. As far as black goes, you're right that it will not be as noticeable but I would still do it; the overall look is improved.

Here is a pic of my 3.0si with 20% tint and 20 inch Y Spokes w/flares. This will give you a better idea.