Maybe this helps:
E36 - 3 series from '92-98
E46 - 3 series from '99+ (replacement for E36)
I believe the E39 is the 5 series from about '96-98 or so (I could be way off here on the years..) and the E34 was the 5 series before it.
Some BMW trivia -- anyone know why early '90 7-series are so cheap? They're priced comparably to 3 series of the same year and are usually a bit cheaper than a 5 series of the same year.
I had a friend with one and he said the set of spark plug wires for the 7 came as two parts -- one for each "side" of the engine and each one had 4 plug ends. These were $600US PER SIDE if (when) they needed to be replaced.
And people asked why I bought a 300SDL rather than a BMW 7-series. They look at me funny when I say I haven't spent a penny on plugs or wires in over 2 years.. meanwhile their BMW's have cost hundreds or thousands of dollars over the same period...
'83 300SD 335,000km (207k) mi
'87 560SL 163,000km (101k mi)
'86 300SDL 356,000km (220k mi)
'92 500SEL 250,000km (155k mi)
'90 300SL 140,000km (87k mi)
'01 S430 260,000km (161k mi)
'03 SL500 167,000km (104k mi)
'07 GL320 CDI 4MATIC 289,000km (162k mi)
'07 S550 4MATIC 170,000km (105k mi)