rear silencer missing

had to pass em like this before so I feel for you,excess deteriorated aint there any more either,as long as it aint gonna fall off or excess noise your stuffed.

7.3.1.1 emissions could not be completed ?

i am with ht here emissions not tested dont forget noise can be assessed at all rev range even at idle would be noisy above normal

If the car is originally fitted with a tailpipe that extends to the edge of the underside of a vehicle,this will prevent exhaust gases from entering the passenger compartment of the vehicle.
However I would be concerned if the exhaust terminated before that which the system was designed and would fail on 7.3.1.1

Removal of the rear silencer on my own vehicle increases noise level by 1Db. Would you class that as clearly unreasonable? It's also difficult to assess levels of noise increase if it's not a vehicle we see on a regular basis

I think the key words here are "clearly unreasonable". In other words, without a shadow of a doubt the noise is far more than would be expected of the same car in a similar condition. That obviously needs to be judged on a car to car basis. If the car is fitted with multiple silencers, losing one probably wouldn't make the noise level "clearly unreasonable". If the rear silencer was the only one fitted as standard, losing that could make it rather loud.

As for emission testing purposes, I can't think of a scenario where a missing tail pipe would prevent you carrying out the test?

Things you do when young bored and have a mate working at a noise testing facility. Got a 4Db increase from removing the airbox tho

Had a few vehicles in over time with rear exhaust silencers missing, didn't even know they were missing until I was doing the underside inspection, just shows how good the vehicle designers are now with modern engineering standards.

Had an Audi A4 diesel in today, the air box under bonnet was incorrectly assembled, it was loud enough to be clear that a fault existed, but no mot fail for that one listed. 

Haha I know a few birds like that