Well if they don't have a acutual reading then you could have been doing any speed, if they are assuming that you were doing 90+ the judge should really not listen but it doesn't always work that way. Technically by w.a law they have to provide a electronic reading of your speed, If you just accelerated fast off the lights to the speed limit you need to say that to them. If they can't prove that you were speeding it comes down to your word verses the police, plus you said you had people in the car so theorically you have a witness or two. All I can say is be honest and up front with your statement and make sure your you know what your goin to say, Its really intimidating being in the courtroom but if you have a half decent lawyer he should really be making a good defence for and looking out for your best interests. All else I can offer is goodluck, the only other constant with the W.A courts is that they are unpredictable