allright son, do not tell the judge that your cars shakes violently, very bad idea. However, you really have no other excuse to use.
If you can think of a really good excuse that would expain why you were going that fast at that time, which you didn't tell the officer at that time which is ... [insert excuse here] ... then go with that.
Lawyers are really expensive and tend to just do the minimal, I would not recommend this plan cause you probably have more options.
Also, why can't you plead guilty..... it will save you in a situation like this...
What you should do is go talk to the judge on your court date and explain the situation straight up. Tell him that you would not normally be speeding under any circumstances, you weren't in a hurry or anything, and that there were no people and/or traffic around at the time. Simply explain to him that your car was having tremors at speed(specifically say what speeds, like 45-70), and you thought that it was an issue that would go away with speeds greater than x speed because you were hoping that it was not serious because you had very little money to fix it because you are paying for college/car/loan etc... (add that it did go away even if it didn't) Admit that you were speeding and that now that you look back on it, it was a really poor decision that could have turned out poorly, via an accident, injury or whatever. let the judge know that you know what you did was wrong, and assure him that you would never/will never speed again, and that in the future you will take your car into a shop before attempting to solve the problem on your own.
Honesty pays off. believe me.
^^^^ yes there are some issues with the solution I described above, but this is your best option. Pleading not guilty will almost always result in the full or maximum penalty because you know you were speeding, and the cop knows that too. You really don't need a lawyer, unless you have extra scrill sitting around that you want to dump into something that may or may not work.
I'm assuming your ticket was in the 800-1200 hundred dollar region, and if you are under 18, you are lucky they didn't impound your car. That being said, the judge will most likey reduce you fine because he can't just let you off. If you do get the fine, ask to set up a payment plan, it works out to like 30 bucks a month depending on what state you live in. Also, you will probably recieve points on your driving record, which are bad cause they raise your insurance rates and affect your eligibilty if you ever want to get a job that involves driving. You don't want points. Try to work out a deal where you get no points, and like an increased fine. Also ask for community service if you don't want to pay the fine.
hope this helps. pm for questions.