can i just cut the wires going from the subwoofer to the speakers and connect them directly to the car speakers ? (and it will work i mean...? )
probably. They are just speakers. You'd only really have to worry if there was a crossover driving the satellites. The set you linked is a pretty cheap setup so it probably doesn't. They likely just straight drive them.
but if they have a crossover and have cut low frequencies to the satellites, you won't get good sound reproduction out of the replacements (car speakers or whatever.) because they won't have a full range audio signal going to them and would be cut-off of low frequencies. (google "crossover basics" for more info)
be sure to measure the ohm rating of the speakers you cut off to make sure they match the 4 ohm car speakers you are replacing them with.
also, is your "G" key broken?

*suggest