My family and I are travelling to peninsular Malaysia in the summer. We are looking to use long-distance taxis for the majority of our travel, but I am under the impression these normally carry 4 passengers, which is bad news for us as a group of 5. How prevalent are long-distance taxis suitable for 5 people and 4 bags (preferably MPV size), and if not easily obtainable through the usual routes (eg. Pudu Sentral in KL), how would one go about finding one? Thanks.
You should be able to contract (schedule) a long distance, one-way, car and driver through most hotels. They will pick you up wherever you request.
You will pay a premium for this. You can reasonably expect to have to do some prior coordination depending on vehicle and driver availability.
Alternately, there are numerous tour companies that you could coordinate your car & driver requirements through. I am partial to toursbylocals.com but there are likely other options available.