iamgort

Anyone able to tell me the max length I'd be able to fit into an a4 trunk with the back seats folded down? Trying to determine if a large box that is 50" long would fit.

precinder2

I don't know about the max length but a 50" inch box will fit easily. You almost don't even need to put the seats down.

UmIsThisThingOn

FWIW, I fit my exhaust in my car once I had my Milltek installed.
So that was about half of the car's length.
That was with it split in half from the clamps backwards (if that makes sense).

audi8k

Yes, 50" length is no problem. (You know that the "floor" will not be flat.)

You don't say if it's a sedan or avant but my notes from measuring my sedan gives a length about 1.82m (71"). Since the rear end is curved and at least the sedan trunk lid inside is irregular, the max length depends on the width.
(This is for me. It might be shorter if you need the front seat at a position further back.)

The Audi official width is 1.00m (39.37").
The Audi official length with backseat up is 1067mm (sedan) and 1027mm (avant). From measuring, that can only be valid for a low and rather narrow box.