Why do people behave in this way

[Acacia98]

11 hours ago, NuevoYorko said:

It's possible that the friend said they'd have to get a new roof box as a "subtle hint" that they really might not be in the position to do this favor, and hoped that the OP would say "oh nevermind, don't bother buying new equipment for your car that you don't necessarily need for yourself so that I can save some money."

OP did not,  Fine.  

There's also this bit: "I did say a few times don't worry if it's any bother, and every time he's insisted that it's fine."

[basil67]

Perhaps it is fine and he just hasn't got the box yet.  I can't see that OP has answered my question about when they are leaving, so it's hard to say if OP is chomping at the bit or his friend is leaving things till the last minute.