It is possible although it may not be a great jump in quality (if at all. and audiophiles hate the idea) it will enable you to get a bigger amp and therefore speakers.
If you have already upgraded the HU and haven't upgraded the speakers when you did, it might be worth while putting some decent upgraded speakers in first, you never know you might have a decent output from the radio/HU but are being let down by the speakers.
Anyway post some pic's of this install and more info on the upgraded HU.
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it say it's about equivilent to an fm modulator
Now I just run the carpc straight to the amp.
I live just down the road in Reading. Reckon the other half would love your cab, being a fan of Lucky Voice.
i also have a 1kw invertor. just run the smoke machine off that tho.
smoke machine Hmmmmm, speed cameras hmmmmm
Welcome to the taxi driver/pc operator for fun & profit club, Mark. Afraid I beat ya to the punch by a bit tho. Best of luck.