an Audi A6 saloon? What about BMW 5 Series? I know they don't in a 3 series but what about the rest of the Audi, BMW, Mercedes etc range?

 

Which A6?

The previous shape certainly did in mine...Would think that the new one would too.

 

http://www.pistonheads.com/sales/597549.htm this shape

 

See the split (40/60) so yes:

 

If you're talking about older 3 series like the E36/E46 folding rear seats were an option in the saloon. Touring and coupe had them as std I think. Not sure on the E9X versions

 

yes it came as standard in the coupe (e46) but not in the saloon very weird as it makes the car far more practical.

 

So there is enough room to store a couple of dead bodies with the back seats down?

 

Don't need to put the seats down for that 3 will fit I reckon, more than that yes you'll need to put the seats down.

 

We ordered them in our E46 saloon as an option - wasn't too expensive and like you say, can come in very handy.

Also have folding rear seats in my E36 saloon. Funnily enough, 2 of the 5 E36 saloons I looked at secondhand had the folding rear seat option on