My three and a half year old boys are very into Cars and these underwear have been a big hit.  I bought them size 4T and they fit well.  I knocked off one star because, while they are tagless, there was a tiny tag on each of them that was very itchy for one of my boys and caused him to constantly scratch.  I used a seam ripper to remove all of them.  You might be able to rip the tags off too.  I gave one a tug then didn't feel comfortable proceeding with that route, but I'm sure it's possible.  Overall I'm happy with my purchase but just a heads up about that tiny tag!