I'm planning to see some friends in Toronto ON and Buffalo/Batavia NY. The plan is to fly into Pearson, see my friend in Toronto, then drive across the border at Niagra to Buffalo and Batavia, before driving back to Toronto to fly out.
My question is, is it possible/is it worth asking the immigration officer in Toronto if they can pre-clear me for the land border crossing? Would it help shorten the time I have to wait?
I am a UK national who has been to both countries multiple times on the VWP with no issues, so I'm not concerned about getting in (though I am planning to stay with my friends so won't have proof of accommodation, but that's another question), just if it would be worth doing it in the airport to make the crossing faster.