I'm selling a Mont Blanc roof box complete with cross rails from my 3-series E46 Touring. Should fit any E46 3-series though.
I think the capacity is 120L, as it's the full width type. Very easy to fit. Leave the rails attached if you only use occasionally.
This has been used once only for a holiday and I have since sold the car. Therefore it is pretty much as new other than a couple of small scrapes where it has been stored.
£100 for the whole lot.
Probably best to collect from N.London area or I might deliver within M25.