Some say it matter, others say it doesn't make a difference. Just get some descent ones. If you're doing a long run, from the front of the car to the back, make sure u get some with good shielding of course to keep the noise out.
At audio frequencies there are really only three things that impact the sound. The following is a quick & dirty on the subject, and is a bit light on the science, but you should get the idea. Note: applies to speaker wire and RCA cables.
1) Inductance - don't make loops with your wiring.
2) Capacitance - not really an issue with any standard wire made for audio, either RCA cables or speaker wire.
3) Resistance - the method of terminating the ends of the cables/wires does matter - even removing and replacing a cable can clean up the end reducing resistance on a cheap, poorly made cable.
My opinion, for what little that's worth, is not to pay big bucks for cable hype (the wire in between the ends is nearly inconsequential), but do look for a cable that has plated ends, and that seems to be well made. YMMV.