Nitrous is an option and I was going to raise it but someone beat me to it.

No one (that I am aware of) makes a kit designed for the car. You will have to do a custom install which is not a bit deal.

I know a guy with a 125 shot in his SLK55. Makes a huge difference.

Not a route I would go but plenty of people use Nitrous without a problem. Don't listen to the hype on the internet where people have blown up their garage or something stupid with Nitrous. If you read the stories you will see the people were all idiots.