Yes you will need a car to move around. Good spots are well hidden inside the oil palm plantation around the airport. You can contact the local spotters for help. Just hope that the weather is fine, not hazy, cloudy or rainy which is about 90% of the time nowadays.
There is a viewing gallery accessible from the land side of the main terminal building but the glass is filthy and with the single runway operation nowadays, not much except MH
734s passed in front of it.
Rules are made for the guidance of wise men and the obedience of fools.