This was my first race internationally while I was living in Asia.
Unfortunately it was a few years ago and I can't remember the details of the expo but this is a big race for Malaysia so I'm sure you had most of the Asian equivalent for vendors present.

The race starts about a 20 minute walk from the Petronas Twin Towers (Also knows as KLCC in maps). For parking I used my office which was a few kilometers from the start however I would recommend staying in an expat friendly hotel nearby and walking from there. Now, unless things have changed your online maps and the local maps wont match in many cases for street names (Jala means street in malay) the reason for this is that the locals use landmark references and not the proper street names so just follow the other people wearing running gear and have some Ringgit tucked away for a taxi back. (make sure they run the meter and pretend you know where your going so they don't drive around town on you. You could also walk with google maps just watch for the motor bikes that drive everywhere)

The race it self starts with the the full and half marathon mixed together. About halfway through the race the full marathon branches off as the half marathon runners head back for the finish. KL isn't a flat place my any means and the road layout makes absolutely no sense to anyone from the western world so you will be running over some water ways as well as many overpasses. The website does list the current elevation profile and it shows a 90 meter incline over about a mile. And I need to tell you all right now that the 2016 course isn't the same as it was for 2011.

I suspect the finish will be the same even through the route has changed. When I ran the race they have a split in the road between the half and full runners about half a kilometer away from the finish. As you get closer this becomes a solid barrier so make sure you're on the correct side.

You finish at Merdeka Square which is where the British turned over control of the country to the Malaysians. So there is some history to be observed as well as a very large green grass cricket field to take a break on after the killer marathon you just ran.