I am familiar with the word заебать [zə(j)ɪˈbatʲ], but I do not understand where does the word как come in picture. This surely doesn't change the meaning of the sentence, but a little explanation could be in place.
The way I'd figure out this is; the sentence Да ты заебал is translated 'Im sick of you/You sicken me/I'm tired of your shit'.
And logically, my guess here would be 'You really piss me off/You make me mad'. Is this close?
In comparison:
Да ты заебал - You piss me off.
Как ты меня заебал - You (really/truly) piss me off.
And yes, I do know and appreciate the speed limits in Russia. Let's take it easy.