Jeremy Hart played with Hot Wheels as a kid, but he eventually grew out of them, tucking the miniature cars away in a toolbox. Then nostalgia struck when he attended the Hot Wheels convention in California with his son three years ago. “I get these little glimmers and glimpses of memories and feelings when I look and see those Hot Wheels from my childhood,” Hart said.

Today, the 48-year-old has fully embraced his inner child. He has spent hundreds of dollars on Hot Wheels and is always on the hunt for new ones that replicate vehicles he’s owned or that were featured on TV shows he watched when he was younger, such as “The Fall Guy” and “The Dukes of Hazzard.” Hart proudly displays his collection at Dent Express, the auto body shop he started in Torrance, Calif.

Hart is part of a growing number of adults who are buying toys for themselves, reclaiming memories from their childhood and showing off their fandom on their desks and shelves. Some have managed to cash in on their obsessions, building up lucrative followings of toy fans online. Toy companies including Mattel, the Lego Group, Hasbro and MGA Entertainment have taken note of the rise of these customers known in the industry as “kidults” and increasingly are making toys with them in mind.

Mattel President and Chief Commercial Officer Steve Totzke said that while the El Segundo-based company has long counted adults among fans of its major brands such as Hot Wheels and Barbie, sales to adults have grown ov.