No, but it is nice if you want to play loud music.
One can purchase car speakers and sub woofers from most car accessories stores including Halfords. They can also be purchased online at Argos and Amazon.
No it will not damage sub unless its raining or something.
ground it to the body of the car floor board
Normally 1 or 2.
YES
YOu can more than that make that hoe bang hard
200 watts
Best Buy and other electronics retailers stock Pioneer sub woofers. The can also be found at Amazon and other electronics retailers on the internet such as Overstock.
not 100% certain but i dont know of any stereo's that you cant add a subwoofer too you will however need a power amp to drive the sub.
There are a few positions for the sub woofers in a car. However the best place as to not destroy a persons ear drums and give the most room is in the trunk of a car.
its the same year round
It is the impedence (coil resistence)normally sub component (drivers)are in 8 ohms impedence.2 in parralel is 4 ohms and 4 in parralel makes it 2 ohms.