Don't have to. I have had 4 different head units in my Limited roadster:
1. OEM Becker non-nav unit.
2. Sony Model No. CDX-GT54UIW ( has 2v pre-amps, had to use speaker wires. )
3. Blaupunkt Melbourne ( plug & play )
4. Alpine IDA-X001 - ( has 4v preamps, I could use the RCA jacks. )

I'm done here.