I remember you made a really nice car from playdough!
粘土はplaydough(もしくはplay-doh)といいます。
The car you made with playdough was really nice!
粘土で作った車、とても上手だったね
You made a really nice car from playdough!
粘土でとても上手な車を作ったよね
I remember you made a really nice car from playdough!
粘土でとても上手な車を作ったのを覚えているよ
(メッセージカードに書く言葉ですので「~を覚えているよ/I remember~」という表現も使ってみました)
以下もご参考になれば幸いです。^^
電車のおもちゃでいっぱい遊んだね→You played with toy trains a lot!
粘土でとても上手な車を作ったり、電車のおもちゃでいっぱい遊んだのを覚えているよ→I remember you made a really nice car from playdough and played with toy trains a lot!