Not sure if you can tell if iDrive is fitted without the VIN. If you know the VIN, there is a web site you can use to check the build sheet which will show you everything (on phone and don't have the URL handy).
The Entwicklung code (e-code) is a body style designator. E90 is a sedan, E91 is the touring (wagon), E92 is the coupe, and E93 is the cabriolet. Note that the Entwicklung code won't differentiate between engine models/lines, i.e. an E92 is a coupe, but could be a 328i or 335i.
Last edited by andrew b; 10-05-2012 at 05:17 AM.