A blog post i read written by an expat in KL. I’m just gonna copy and paste it here:

FAQ: Driving in Malaysia

1. What side of the road should you drive on in Malaysia?

99.7% of cars drive on the left hand side, 0.2% on the right hand side, and 0.1% drive in reverse (be on the lookout for drivers reversing at high speed in the left hand lane of freeways, having just missed their exit). Therefore on the basis of ‘majority rules’, it is recommended that you drive on the left. However, be aware that only 90% of motorcyclists travel on the left hand side – the other 10% ride in the opposite direction or on the sidewalk. Fortunately, motorcyclists traveling in reverse are rarely seen. read more