50mph in 6th in a Zed would sound awful... like a strangled fart
I have been through the Dartford Tunnel in my Zed maybe 200 times in many combinations : stock, stock + pop charger, Buddy Club + pop charger + plenum spacer, Buddy Club on + no pop charger (as my ears bled), milltek (bit quiet), milltek + berks
Mostly 50mph in 3rd at about 4k and quite a few