Throw up as detailed a listing as you can muster. Post it on M5board, Bimmerforums, Autotrader, Kijiji - everywhere. I sold my E46 on E46Fanatics, which is primarily a US-based enthusiast community. Just make a note that it's a Canadian sale before the price police on US forums jumps at you.
It will sell eventually, seems to be a very nice example of an unmolested E39. They're getting tough to find.
Imola Red / Imola Red ///M5
E60 SSK, Dice iPod, Illuminated ZHP knob, MKIV, Euro Armrest, GT ExhaustDaily:
BCR Coilovers, 19x10 + 19x11 Rial Daytona Race, Michelin Pilot Super Sport
'04 E55 AMG Brilliant Silver on Anthracite
'96 318i Alpine White on Black
'01 330Ci Titanium Silver on Coral Red
'96 328i Jet Black on Black