Bringing your car into Nepal
I have brought in a number of motorbikes into Nepal - rode up from Delhi, then spent 2 to 3 weeks in Nepal. I did not have a carnet but just paid a temporary import tax - I can't remember how much, but it was not expensive. The age of the bike was never questioned. The Nepalese authorites were just trying to stop vehicles being illegally imported. I have come in through 3 different border crossings and never had any problems - and even extended the stay of one of the bikes up in Kathmandu. I suggest you just go up to the border - say at Bhairawa, and ask the officials, in the main they are very friendly. You can also get your visa at the border. The main trunks roads you will use are in pretty good condition theses days, stop off at Butwal Hotel Siddarttha is good, the Butterfly Lodge in Pokhara, cheap and excellent garden, Kathmandu there are loads of cheap places the Mustang Holiday Inn is not bad and if I remember right you will have place to park your car.