A BMW tii exhaust manifold, part number 11 62 0 743100 costs about $90 devoid of injector tubes or EGR fittings, slips on a 320i, and mates with the exhaust pipe flange as though it had been made for it.
A tii heat shield, part number 11 62 0 743130, makes it look “factory” and costs about $15. The stock heat shield will no longer fit.
Note that the superseding numbers for the above parts are 11 62 1 265 449 and 11 62 1 262 130. You can order by the description or the old number, since the parts person will find the superseding number and get you what you want. Tech Ed.