Leaderboard

I went with some products from Car Builders : 1) Insul-Layer - applied to inside of doors and rear quarter panels 2) Mass Noise Liner - used in place of the old sisal under carpet areas and on the firewall. From their web site : "Sound deadener is generally a misunderstood material. Normally the first stage of treating noise is referred to as ‘sound deadener’. This stage only really treats vibration in panels. It was often a bitumen-based product but more commonly consists of a butyl rubber with an aluminium top layer. Cheaper sound dampening sheets consist of a lower grade butyl, which is not as durable or resistant as those used by leading brands. Butyl sheets by themselves however, will not result in dampening droning or external noise that you may be more interested in treating. This will be treated more successfully with mass loaded vinyls. If you are aware of the type of sounds that are annoying, you will be able to treat them more successfully with targeted products."

In our shop, from bare metal we Epoxy, then prime, then mask off the rails, stone chip the flat panels, then apply body colour over everything. IMHO This is the most professional way to go about the underside of a Z: