Just to give you California traveliers a heads up, last month I was northbound on Highway 101, just north of Eureka on a weekday morning with 5th wheel in tow, the CHP had a temporary checkpoint off to the right, he took a pole with a mirror and looked under the truck, he never looked under the hood, he asked me to rev it up just a little no smoke, and see the registration, it took about 45 seconds to complete, I don't know if this is a one time event, or not, I didn't ask, there was a big rig who was next in line, never had that happen before, or since, just something to think about