Been reading reports of people sending cars, getting an error and then the car has disappeared from their garage and not arrived at the other end either. Kinda stuck in limbo...
I tried to test it out; created another user on my PS3, completed the B licence and tried to send a couple of cars, a horn and a paint colour to my main PSN. They all appeared to send correctly, and cleared from my garage, but over 12 hours later they have yet to appear in the garage of my main save!
I am able to message between the two accounts, but it seems that the gift sending function is flawed - unless of course it's aware that they are both on the same Playstation, but what if there were two people in one household using the same console who wanted to exchange vehicles??
It's a mystery to me as to where the vehicles went!
I have checked the gift receive bit in the community tab and there's nothing there either
Update:
Just tried again, sending some paint and a couple of museum cards, and they appeared in my community gift box as soon as I loaded up my main account, so it looks to be a bug of some sort!