"So you can't see me either?" It's said with a small amount of resignation. Maybe some silly part of his had hoped Bucky would be able to see him, even when no one else has been able to. Bucky's always seen things in Steve that other people hadn't. Why not take it more literally this time?

He puts the car back in drive and starts rolling slowly forward again once Bucky's securely in the passenger seat with the door closed.

"You're the first person I've found out here in hours, Buck."

Those words are easier than what he wants to say. Bucky's the best looking thing he's seen all day, even if it's all some trick. Steve's lost Bucky too many times. No, he's failed Bucky too many times. He's not sure how he's going to take it when it turns out this Bucky isn't even real. Will he crumble away again or just disappear?

Maybe it's Steve who's going crazy.