Upgrading rv stereo to a car stereo

Here's how I did it in my trailer. I fabricated a place to mount the dash head unit where the old stereo was. I took the time to add a better antenna and larger speaker wire, which I routed to the new speaker locations. I also routed wire to a new self powered subwoofer. I found that the new stereo would pull too much power from the OEM 12v if I turned it up, so I added amps near the speakers, which in my case was also near a good 12v source. The amps and subwoofer are all controlled via the power antenna lead (had to run wire for that too). Ultimately it would have been very difficult to run new 12v to my upgraded stereo. Adding amps after the fact allowed the stereo to run lower power and all the components are happy. By the way, I intentionally selected a head unit that had audio inputs in the back so I could route the TV through it too. I should add that I've reserved the space under my sofa for electrical/electronics. That's where the sub and amps were installed.