I bought my DH a dinghy for our sailboat for Christmas one year. My old college roommate picked it up at a store in Detroit. Then we transferred it to my car at a U of M football game in Ann Arbor. Hid it in the neighbor's garage for 2 months. Transferred it from the neighbor's to my car on Christmas eve. On Christmas morning my DH, who has guessed EVERY SINGLE GIFT for over 30 years, only received an envelope on the tree. The envelope led him to another envelope and so on. Probably had about 10 TOUGH clues. (Sorry, but I was lovin' every minute.) It took DH 2 days to find the gift...we had to play the "getting hot, now you're getting cold" game for him to find it. He walked by my car at least a dozen times but never looked in.
My in-laws thought that I was cruel....kids and I enjoyed every minute of it. We had him searching outside and in the woods and everywhere imaginable....I have a smile on my face as i type!!!!