Reasons why you can’t generalize on Malay drivers
They are neither fast nor slow
It might happen that a driver blocks the left lane on the freeway going 50km/h, and at the same time another driver blocks the right lane, overtaking going with 60km/h, although the rest of the road is completely empty. On the other side some kid might want to show you that his tuned Proton Wira makes it from 0 to 100 in less than 20 seconds by fully accelerating in a pedestrian zone.
Some know, some don’t
Asking a driver for the way either offer you a detailed description, and if you are a little slow in understanding actually show you the way with his car – or another drive might guide you directly into the wrong direction
Taking care – or not
Overwhelmed by KL traffic, there are actually driver who would let you change the lanes waving, that you are allowed to join into your desired lane, but I think most of the time you might just try to change the lane aside of an elderly Chinese lady, who is too buy eating some rice while driving, or a Malays family with 3 kids bugging around on the front seat, which would not even notice you.