Just took delivery of this 2018 Club Car Precedent unit and top speed is 13.2 mph and have questions about the speed code setting. Serial # prefix is JE18. According to what I can find, this is the Mode 2 speed code. Mode 3 is 14.6 mph and Mode 4 is 19.2 mph. What does it take to get this unit up to Mode 4? I'd be happy with that top end. Can anyone offer some advice?