Yes, if possible.  This can be difficult but it can save time and money. Technicians charge by the hour for time we have to spend driving and diagnosing the car. If we know the problem only happens on the highway at 100 kph, then we'll head straight to the highway for a 100 kph test drive. If we know the problem only happens when the car is cold, we won't waste hours testing a warm car.  Of course, don't worry if you can't duplicate the problem, we will do our best to find it based on the information you provide us.