Most parts will be the same for all vehicles with the same E designation...most.(someone correct me if I am wrong, it wouldn't be the first time.) If someone says it's a E34 525i this is how you would enter it correct? 5 Series > E34 > 4 > 2.5 If it is an E34 540i it would be entered 5 Series > E34 > 4 > 4.0 E30 318i would be 3 Series > E30 > 2 > 1.8 I am not sure how you would enter M's into that system... I guess E34 M5 would be 5 Series > E34 > 4 > 3.4...since that is the actual size of the US Spec engine. E36 M3 might be 3 Series > E36 > 2/4(depending) > 3.2 The M's really screw that system up unless they have a special way to get to M stuff. I don't guess I have much to add, I doubt any of that ramble helped much. Tomorrow some of the other guys might be able to help some more.