i have a '99 dakota sport, reg. cab, and i have sony 10" subs, a dual 460 watt amp, and a rockford fosgate cap, im just wondering if i need the cap at all? the subs run at 300 watts, and the amp is 460. i wasnt sure if the cap is really needed at all?

you will get by just fine without it. do your subs run at 300 watts rms or is that the peak wattage? also, if you are running a sony amp, you will not get 460 watts out of it (that is rating is probably only if you bridge it into a 4 ohm load). you can probably plan on getting a good 175 watts to each sub with it, which is about what you will want if they peak at 300 watts, which is the way sony rates their subs.