Yeah. Too loud....and:
Most hiphop records I hear use a continuous line like that with a high-pitched synth...way in the background. But there's an essential element missing in the construction, I think: something grooving with the kit/bassgt..knitting together with it. If I had to go with just guitar parts, and no whistling synth line, I'd focus on a syncopated guitar...James Brown-ish...to make the bootie move. The sound and playing is real ' 60's Philly Soul'...a really cool stain that's due for a comeback...very urban and honest and organic. It's not something I've heard a lot of. None of that overdone electro-thump that every song like it has. I totally dig your concept and sound; but the guitar has to learn a groove thang to put it over the top.
Grab some old 60's Motown and Philly...listen to the guitar. Sly, Stevie, Temptations, ....Thomas Dolby's 'Flat Earth" has a guitarist who does it real well....Squeeze's "Tempted". Jimi Hendrix was a master of the style...when he wasn't wailing on '11'. Prince's stuff is a real good schoolin', too.
"chicca chicca wah wah beedle-deedle..." Nice repeating figures that mesh like gears with the other parts.
I think it would make this tune, and others like it you've written, really, really popular.
It's not easy to do...it'll take some dedicated work...but that ability is a really important tool for a guitarist to have in the 'kit'.
Your tune is a refreshing straight-shot of soul sound...just get the guitar jumpin' and you'll probably sign a contract.
cobbled together something to illustrate a bit:
http://www.yousendit.com/download/dVlwR0lUTStlM1FLSkE9PQ