My two cents...

First thing to do is to research the county/state to see what you need to get a reduced fine and/or infraction. Some courts bend over for you if you bring a lawyer, others will make you a reduced-fine deal just for showing up and not looking like a gangster (e.g., MO and CT, respectively). Go to court (with the lawyer, if necessary) and be prepared to pay fines in excess of the ticket for a reduced, non-moving violation. As suggested, you will save thousands in the end paying $250 for an illegal parking infraction rather than $100 for a speeding ticket plus an extra $1000 a year in insurance for the next 5 years.

Your scan gage data will most likely not be of any use as evidence, since it is not recognized by the court as a legitimate speed-data-collection instrument, although it is worth noting to the prosecutor that you have this additional instrumentation and a working speedometer, and they both showed your speed as "at least 10 mph lower" than what the cop wrote up. It'll open the door just enough for him to think the case against you may be a little bogus.

Incidentally, some states (notably CT - not sure which others) will sometimes offer a "charitable contribution" option if your speed was not excessive and you have a decent driving record. This is the Holy Grail of getting-out-of-a-ticket as far as I'm concerned: You get a ticket that would run you $150. The prosecutor offers you a reduced fine of $75, but it's still a speeding infraction (i.e., moving violation - with points). You let him know that it's not so much the fine you want to reduce as the infraction, then he offers to let you make a charitable contribution in the amount of $150 in exchange for reducing the charge to illegal parking (i.e., non-moving, AND NO POINTS). You say, "DEAL! Thank you very much!!" The bailiff right outsidde the court room collects for United Way, you write him a check, get off the moving violation, then write the $150 off as a deduction on your taxes! Talk about win-win!!

Full disclosure: this advice is from someone who has gotten well over 40 (and maybe over 50 at this point) speeding tix in his 21-year driving career, and still pays normal insurance rates.