Gift ideas for a three years old?

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My son is turning three and we don't give a lot of stuff, he has everything it feels like. He will get a new room for his birthday, but I also want to give him a toy or so, so he gets some real presents to open. Any ideas? He likes vehicles, but sadly doesn't care for puzzles, painting, play-doh etc. I'm thinking he'll get some books, because you can never have enough, and some pjs.