Aside from Barricade, who was obvious.  

You wouldn't have to have super sensors to notice Megatron crashing into the street. As for Ratchet, I think he meant that more intuitively, than literally using sensors. Sort of like "I sense a storm is coming," but from gut feeling, not from looking at the radar.
The building where the Autobots looked at the glasses, by the way, was Griffith Observatory in L.A.

 

Was it jut me or did his head kinda animate and look like a muppet when he says that?

 

I was talking more about Brawl, BoneCrusher and Starscream

Bonecrusher had like a bulldog painted on him...

I though Barricades design was pretty unique...

 

.Barricade's Decepticon Insignia, I think, is encircled by the Police Insignia (I'm not sure)
.In 3 Pictures of Bonecrusher in the "Autobot/Decepticon Pics" thread show the Decepticon Insignia is upon his chest or somewhere higher.

I had one or two more Decepticons that bore the Insignia, but I think the slurpee I'm drinking is frosting my brain.

 

Yeah, Barricade's Decepticon symbol is inside the police shield. I wonder where Brawl's symbol is..