You could and it will work but I really wouldn't recommend it. I'm not sure what the expected minimum input is on those car speakers but I bet its probably more then the 6 watts the z506 offers you. At least the Ohm's match. See below for specs of that logitech system.
Z506 speaker
Satellites: 2 x 6 watts (RMS) (into 4 ohms, @1kHz, @10% THD)
Subwoofer: 21 watts (RMS) (into 6 ohms, @100Hz, @10% THD)
Linked speakers
2 x car speaker - 6" x 9" - 3-way - 45 - 20000 Hz - 4 Ohm - wired (Claim to be 600W RMS but some reports of 350RMS)
To run those speakers and to run them happily you would want something like the Logitech Z906's
Total watts (RMS): 500 watts
- Subwoofer: 165 watts (6 ohms, at 52 Hz, at 10% THD)
- Satellites: 335 watts RMS (5 x 67 watts per channel {4 ohms at 3.85kHz, at 10% THD
My Jukebox runs from a set of Logitechs very similar to your linked set and it sounds fine, If I want more sound then I just switch over to the output to a separate house amp and speaekers which has 400W RMS and generally has the neighbours complaining.
If the 906's are out of your reach then see if you can find a set of z5400's I use those for my HTPC and they have plenty of power.
Hope that helps a bit.