Is he going up near Sepang? That's where all the car tuners go to test their cars out (refer to my photos!) and there are plenty of car tuning shops nearby. Is your friend a local? If not, you might be better off going to Singapore as they tend to be easier to understand. Make sure you provide him with the correct part number to buy so he can check it against the item they try to sell him. If u want exact area to go to (warning: this area is not well suited to non-locals) then PM me and I'll get it for u asap from my cousins.
