Why just the owner?
I'm not addressing the searching of the vehicle though..That sounds a bit odd for a speeding ticket.
Anybody you know could smoke cannabis. If you're against cannabis, then you won't ever know they do. So, what are you going to do if you catch a ride with a friend and he get stopped with pot in his car and they arrest you?
Will you suck it up and just go along with the presumption of guilt, pay the $125 a week for the year you get probation and accept the bust on your record? This is exactly what happened to a guy I know personally that caught a ride through Texas.