Liam Bailey made a song named "Villain" and this is rap. Very qualitative rap. While listening to it, you want to move your body to the rhythm of the music, and when it is over – to turn it on again. Most excellent mixing of sound go under guitar, which is present here. Therefore, if it would be such a direction in music as rock-rap, it certainly would have been in that song. If not yet, it should be created.
Reference:More about Liam Bailey on Wikipedia