Why some cars have antennas and some doesn’t, and what the “fin” looking like is doing?

Question

I see some cars have antennas (and some even have two) and some doesn’t.
Why is that? And why some have one or two what’s the matter with the count? And wha the matter with their length and the direction they are pointing?

And what’s the fin (𓂄) doing?

In: Engineering

Answer 1

The shark fin antenna replaces the ‘traditional’ whip antenna on many smaller cars, if it’s centred in the back. If it’s near the front and near a pillar, it’s likely a GPS receiver.

Many commercial vehicles, emergency vehicles, or radio hams will have additional communications equipment installed which uses additional antennae. These are almost always long whip antennas.