The low frequency response is quite good. It does not go below 30Hz but that's something to be expected with this size. The intensity is more than adequate for a small or medium sized car. It Should be good enough even for larger cars too. Do not expect it to blow out your windows or wake the neighbors but if you install it under the seat it will do a good job at filling the low end. I do not even need to use it at full gain most of the time (Usually even below 50%) and of course nowhere near full source volume. Especially I like the factthat it's not really distinguishable from the outside over the engine noise unless the car is stopped (or it's set really loud).
The remote is very handy for adjusting gain as too much bass can become annoying in a long trip. Installation is very easy and the low power requirements mean That You Do not Necessarily have to draw power from the battery. Just check you fuse ratings.