Regardless of the seatbelt issue, the Bolleas are still screwed.
Nick comitted an act that a "reasonably prudent person" would or should know "might" cause death or great bodily harm. He also knows the act is CRIMINAL.
I don't look to see Nick spend any "real" jail time. Instead, I expect to see him loose his license, and the entire family will be engaged in the lawsuit.
The Bolleas, likely the Hogan enterprise, and Nick.
All the kids not wearing a seatbelt or the fact (if they can prove or get the jury to believe it) that the passenger was a compliant and willing co-conspirator in the act, will do is assist the jury and/or insurance company adjustor in subrogating damages.
He (his family) "might" get a few $$ less for not getting out at the first light...
Frankly, I believe the kids were being stupid together. My best uneducated guess would be that the Marine home on leave was pushing Nick into racing and compliant about being there
Does that change the fact that Nick should have said no? Absolutely not. And the Bolleas will pay for that mistake and thier encouragement of such behavior.
Now...lets see what really happens????