[Es2] Rear Main Seal install

[n-engelbert@terrans.net]

Got my donor engine back from the machinist a month or so ago, and I just
started reassembly last night.  My question is:

What orientation should the rear main seal be installed in?

There is a flat on one surface, and on the other side it's cupped with a
spring around the ID of the rubber crank sealing surface.  I'm thinking
that the flat should go to the outside of the engine, but I want to be
sure before I proceed.

The bentley is unclear about this, and the family album drawing isn't too
clear either.

Thanks!

Nathan Engelbert
83 UrQ DA900453
89 90q
91 200q20v donor
91 200q20v avant