Non retro engine number location,

[Vintage75]

I'm going to look at a BMW 328 (2000 X) 
I don't have much knowledge of BMWs and I don't know the location of the engine number on them,
(yeah I know it will be on the engine!! April Fools and all that )
but where do I look to find it , offside/near side/ etc?

thanks for any help, G,   

[86corolla]

should be under the inlet manifold
or stamped on a flat spot just above the sump bolts

[Vintage75]

Thanks.