There's no easy place to mount speakers... that was the main issue. A lot of hot rod 'hidden' stereos exist like secretaudio, etc. but fitting speakers isn't easy.
In the end, I went with the best solution: Ipod and good earbuds (Etymotic 6P)
Amazon.com: Etymotic Research ER6 Isolator In-Ear Earphones (Black): Explore similar items
Which also act as earplugs to block wind noise.