Tall Boy, Small Stroller

My 3-year-old son is tall, very tall. He is often mistaken for a 5-year-old and the normal antics of a 3-year-old can seem like the behavior of a troubled first grader.  But this doesn’t bother me as much as the looks he gets when he falls asleep in the stroller.  He still takes a midday nap, and when we’re out, he falls asleep in the stroller, perfectly normal for a 3-year-old. Except when I’m coming home with my napping boy splayed out in a stroller that is just too small, it looks like a have a drugged child in a wheelbarrow, or worse, another spoiled “Park Slope brat” who refuses to walk and needs to be chauffeured everywhere.  Hey gets stared at as we walk by. People actually stop us and tell me “he’s too old to be in a stroller.”  My wife usually snaps, “he’s only 3.”  I usually ignore them or say “Then I’m glad your opinion means nothing to me.”  But the worst was when a deranged homeless guy followed us yelling “get up and fuckin’ walk!”
And this is with the biggest stroller available.  What’s a sleepy tall boy too do?