Norton gets his suitcase and himself settled into the cab, and once Neal's in as well he'll silently take Neal's hand, keeping it low against the seat where he thinks the driver won't see.

"I really don't like that tracking thing when we know there's someone with bad intentions trying to find you. What if they intercept the signal?" He doesn't know much about how the anklet works, just deducing based on what he knows about things like radar and radio signals combined with his experience with alien technology. But if it gives away Neal's location, it's inherently a point of weakness when trying to hide from ne'er-do-wells.