so should I tell the judge that the cop has no proof that I was following too close because he was in front of me? I know this is not likely to work because the cop is always right in their eyes.
You do not have to provide evidence, you just rip apart the officer testimony since it is only his words and his opinion, and opinion are not fact, just because he think it was too close is not enough in itself if you challenge it.
Most people do not challenge the officer testimony and simple fact you do not challenge tells the judge his words are true. What you want to stay away from is the he said you said argument you will lose. You simple ask him question about how did he determine you were following too close, he did some how measure it, if so what method did he use. then by the law what distance is consider too close at that point he will not be able to say since no laws say exact what is too close. So at point it was purely his opinion not fact that he base the ticket on.
anyway this might help you, it Oregon's own recommendation on following and the site the 2 sec rule
http://www.oregon.gov/ODOT/TS/police/tailgatingbro.pdf
I am assuming you were sited for 811.485 Following too closely; penalty. (1) A person commits the offense of following too closely if the person does any of the following:
(a) Drives a vehicle so as to follow another vehicle more closely than is reasonable and prudent, having due regard for the speed of the vehicles and the traffic upon, and condition of, the highway.
As i said above, following distance is about speed and cars ability to stop and people reactions time. The officer only knows 1 of 3 factors and he making assumption about the other two and police are not experts in physics, and human physiology.
The key to the above law is reasonable and prude and this is subjected and up to the individual.
Maybe he sited you for
811.150 Interference with emergency vehicle or ambulance; penalty. (1) A person commits the offense of interference with an emergency vehicle or ambulance if the person does any of the following:
(a) Drives a vehicle following at a distance closer than 500 feet any emergency vehicle or ambulance that is traveling in response to a fire alarm or emergency.
So you could not have been within 500 feet of him if he was on an emergency call. This law was put in place to keep from tailgating through the automated redlight that turn green in the direction the emergency vehicle is going.