You will mostly likely find yourself sitting on an old, decorated rug in the back seat... with magazine pages pasted onto the door as a covering... and just hoping to yourself that you and the back-end of the car are not left behind when you bounce over a bump (or hole) in the road and hit your head on the roof! It's an experience!
Sarah was able to give me a roundabout fair price for my destinations each day and that helped a lot. The taxi drivers WILL bargain with you and usually want the job enough that they will come down to the goal price that Sarah listed for me. Perrrrrfect. I was royally ripped off my first day and learned from there on. (The driver had also taken me to exchange money... so he knew I that I had plenty. Mistake number one!)
Some photos from inside Kathmandu taxis:
And a local bus... with passengers literally hanging off the back because it is so full!