First off, there is an older model white Tahoe that patrols from Liberty hill to Georgetown.
Cop plates, no antenas. Never runs C/O so he does not give him self away.
The only way you can tell by looking at it is the police rims and hub caps rather than the normal ones. Has a brush guard on the front, but it looks nothing like a police push bar. If he is behind you the eyebrow lights are a dead giveaway. I have seen this one three times. Twice on 29 and once on leander road.
He is a wilco deputy.
The other is a black DPS camaro. Tons of lights and antennas make it easy to spot, but it has no lettering or light bar on top. He runs 183, toll 130, I35 195 and 95 from what I have been told.
The only time I have spoted him myself was on 95 half way from granger to bartlet. I/O only from what I have been told, I know a guy that did a ride along with him and anouther that got clocked going 90 by him.