My question involves a careless driving ticket from the State of: Washington

I was driving in my ex-police interceptor on a road that had a 35 mph speed limit. There was a seperation between my and the opposing lanes--I couldn't see the other lane. The other lane was visible when I was approaching an intersection. As I approached and passed the intersection I saw a police interceptor with an officer inside in the opposing lane. I passed another light and on the 3rd light I turned left (giving a ride to the person in the passenger seat). 2-3 seconds after I made that left turn I saw the very same police interceptor with his lights on pulling me. The officer approached me and began the converstion with a sarcastic "tell me you're duty" --referring the crown victoria that I was driving. He told me that I was probably driving 70mph + and that in that short distance of 4 or 5 blocks he had to drive in excess of 100mph to catch up with me assurin me that he could put the numbers in a certain calculation formula to prove to me that I was in fact driving 70mph. Needless to say, there was no radar involved. I requested the officer's notes from the Mercer Island Municipal Court, and one of the things that contradicted the most was the following: "I am confident in my estimation of the suspect vehicle's actual speed was close to triple the actual speed limit."
I would also add that the road was quite wavy to me it would seem quite impossible to drive over 100mph as the officer claims, with no appearent proof by the way.

The back of the ticket said I can contest the ticket, and until the court can prove the officer's claims, I won't be charged with anything. With that in mind, should I contest the ticket? Should I get an attourney? What are my overall options and choices?

Thank you in advance,

ai2tman.