I have heard that often the immigration officers don't bother stamping the visa, especially if one enters by car. I plan to enter by bus. If they don't stamp the passport, should I ask them to do so? I figure that this way, I will at least have a clear record of entering this year. Please let me know your thoughts on this matter. Many thanks.
Yes, you can tell them your situation and why you need your passport stamped and I am sure they will not have a problem doing it.