No. The officer does not have the right to search your vehicle without probable cause. Just stopping you for a speeding ticket does not give him the right to search. However, if he smells alcohol or sees anything in plain sight then he can search or if you give him permission.
Some officers will search and then make up probable cause later if they find something. Since it is your word against his then you lose.
Once you are placed under arrest you and your vehicle can be searched or if your car is towed for any reason they can search. For example you are in an accident and your car is towed then the police can search your vehicle.
