Best Stereo Receives Is It Possible To Wire A New Car Stereo WithOUT A New Wiring Harness?

Is it possible to wire a new car stereo withOUT a new wiring harness? - best stereo receives

I have a 2002 Impreza's stereo. I just bought and a new set of Pioneer. I forgot to get the cabling. Is it possible without re-wire the wiring harness?

I know, I know ... would be easier with a wiring harness, but I ignore them if possible. Can I do this?