From humble E21 to tech-laden G20, all seven, um, Threes, are here
BMW Reviews and News
BMW M3 - Wikipedia
The BMW 3 Series models at a glance
Evolution of BMW's 3 Series (1975 ~ 2018)
BMW 3 Series: a Journey through the Generations
BMW 3 Series: Every Generation Ranked (Worst to Best)
Here's every generation of the BMW 3 Series
BMW 3-Series: A look back at the first six generations
The BMW 3 Series models at a glance