My car is Subaru Impreza 2009 and today I saw some paint scratch from a rockchip or other car's door. Does this look deep enough to require immediate actions? Also, is it safe to apply clear nail polish to it. I'm quite concerned that it will rust
Thanks
Does this scratch on the door require immediate actions?
No.
That's a very small rock chip, who cares if it rusts in that tiny spot - it's a 14 year old Subaru.
You may want to eventually do a DIY touch up.
just grab a paint pen. They're cheap and you can use it to fix all your rock chips.

Try just clear coat on it, you can buy some for like $10. I have used it on numerous scratches, and often it works so well you don't notice it was scratched. Nail polish just won't last.
Yours may be a bit too deep, but give it a try. At least it will seal it and prevent it from getting worse.
