not to mention finding someone capable of doin gthe job properly. No other manufacturers as yet offer the "in line" turbocharging that BMW does with it's twin turbo units so I assume it's quite difficult to do. And then there's the hole you blow in the residuals of the car by bolting a non OEM turbocharger onto the car....and also voiding the warranty.

Trade in definitely the way to go. Especially is you have a non ED 3.0d.