BMWs can be awfully confusing when it comes to their badging. Back in the day, a 323i E21 simply meant that it was a 3 Series body with a 2.3-liter engine. A E12 535i was the 5 Series body with a 3.5-litre engine — simple, right? M3s were all two-door coupes; except, they are four-door sedans now; and the M4 is now the M3 coupe; the 320i may have a 2.2-liter engine; and the 323i E21 could have the 2.5-liter — confused? Me, too. (And, perhaps, so is BMW!)
