how can I make this car faster with out spending a lot of money it is a stock

Take it to a European performance shop.

160K , Start with a freshened up engine. IF "without spending a lot of money" means spending under 10 grand on it, that would be were I'd start.

Drop in a 427 Chevy....L88 if you can find one! That will do it.....,might be better to go with the other 2 answers though come to think of it.! That much power might flip the car over.... Where you going that you need to go so fast anyway? It will run the speed limit like it is now want it? BTW, don't be mistaken, the majority of us here have forgoten more than most will ever know about making a car go faster!! In reality, it's just not practical to do so anymore....

I'm assuming its the Supercharged AMG S55 with 500HP. Remove the speed limiter. Its set for around 155 mph and the stock car is capable of doing 200mph. I wouldn't spend much on the car as they have low resale values - maybe as little as GBP£4k. To get it faster the cheapest mod would be to lighten the car by getting rid of the couches in the rear with their seats with several motors in!! But do you really need to go faster in this car ? Id spend nothing and leave the money to your heirs who will be collecting soon if you drive at 160mph on the public road!

This is a very fine European built car designed to be driven safely on public roads where other people want to feel safe without worrying about some guy coming out of nowhere running 160 miles per hour and kill all their kids or their entire family. I strongly suggest that you trade your car for an airplane