Here's my $.02. I don't know where you found those "jury instructions", but they rely heavily (along with your "uncle's" advice) on the words "willfully" and "purposely". Yet, the statute reads:
Quote Quoting CVC 23109
(c) A person shall not engage in a motor vehicle exhibition of speed on a highway, and a person shall not aid or abet in a motor vehicle exhibition of speed on any highway.
Not one mention of intent! Therefore, any interpretation of the law which requires "intent" as an element must be based on case law. Neither of you have cited any cases to that affect.

You are certainly free to follow your "uncle's" advice (reads like something off of one of those "trial by ambush" web sites), but please remember what Chucky said about irritating the court. If you're found guilty:
Quote Quoting CVC 23109
(i) A person who violates subdivision (b), (c), or (d) shall upon conviction of that violation be punished by imprisonment in a county jail for not more than 90 days, by a fine of not more than five hundred dollars ($500), or by both that fine and imprisonment.
Keep in mind that the officer is going to testify that you "peeled out" in first AND second gears. If you ask if it rained earlier, he will say something like, "I don't recall, but I'm not in the habit of handing out citations for infractions that might have been caused by the weather." From my viewpoint it's the "first AND second" gear thing that's hard to beat. Anyone can see momentarily losing tracking on a slick road -- but through first AND second gears? Nah!

So, my advice -- get a lawyer.

Good luck,
Barry