I was just wondering if a universal back box would fit my mk1 punto 55 sx. i've heard that fitting a universal one could cause it to lag :S. This is the one i am planning to get...http://www.motor-world.co.uk/show_prod.php?prod_id=11198. Also, how can i find out what sort of sound it will give my car, i dont want it sounding like a tractor!! cheers ryan...