Here is a new manifold entry SPA TMB02, (Looks incredibly familiar to something a couple years ago *cough*) they claim it works with all N5X although realistically this will likely see the most use on custom N54 projects. At 1000 bucks, it may be priced a bit too high for what it is, they threw away a good opportunity by not going twin scroll or using a T4 flange.
This could certainly be compared to the on3 cast top mount manifold, I suppose someone will just need to try it out and see for themselves:
You can find it for sale on ebay: http://www.ebay.com/itm/172741994965
This could certainly be compared to the on3 cast top mount manifold, I suppose someone will just need to try it out and see for themselves:
You can find it for sale on ebay: http://www.ebay.com/itm/172741994965