Halfords??? Best off going to a proper car Hi-Fi shop instead of a chain that has spotty teens serving who think Max Power is a bible and think th epinnicle of motoring is their mums Corsa that's parked at the front of the store after the staff discount has been abused on wanker lights and stick on vents.

For your cash I would get something like;

http://caraudiosecurity.com/shop/pro..._id/12676.html

or

http://caraudiosecurity.com/shop/pro..._id/12471.html