In the garage, I can 'look at your car', but I can't 'look at my car'; It's mine (the player), not yours, right? ('blue car', and 'red car' could also be understood as Will's car and mine.)
I've flagged up this issue on the forum. I have absolutely no idea why X YOUR CAR is working and X MY CAR isn't. I definitely tested this exact issue many times and it was working fine the other day, so I don't know what's happened.
X RED CAR and X BLUE CAR giving correct responses in my editor (no idea why they aren't in-game). I'll do a quick update once I've sorted out the MY issue.