So. I've been wanting to add air ride suspension to my 99' 740iL. But I hate how cheap and ugly most of AR kits look, also I'd like to keep all my modifications as close to OEM style as possible. And fortunately being owner of E39 wagon with rear air suspension, I think I know where to look for inspirations. After few days of studying widely avaible diagrams and topics about how E39 SLS works, I'm pretty sure I can install(I mean just sensors and wires. Shocks and bags still need to be custom made) and code it to work with my GM3 module. But the problem is, if I want to have self leveling on all four wheels, would have to go with EHC II dual axle air suspension from E53 X5. Never worked with one(I despise SUVs lol), don't know if they still use the same General Module. Also, I know that 4.8i version has standard suspension level switch, that lets you increase and decrease ground clearance on about 1 inch(and I really want that with my air ride project), but not exactly sure how it works(my guess is that it's propably connected between sensors and EHC, and simply tricks the latter into "thinking" that suspension is lower/higher than it really is). If any of guys have experience working with X5 double SLS suspension, or any lectures/sources/diagrams, I take it all, as any knowledge will be helpful. Thank you in advance, and may the V8 be always with you