After spending three days ticking off the main attractions in Rome, husband persuaded me and junior it would be worth the bus ride out of the centre to visit here. He can't go past a car museum at the best of times and he is a police officer himself, not to mention a Fiat fan. The bus ride from Via del Corso took about 20 minutes and dropped us just a few minutes walk from the museum. After fighting our way through the Vatican etc, it was so enjoyable to spend some time in a peaceful museum where the staff were genuinely pleased to have interested visitors, even if we don't speak Italian. All manner of quirky vehicles on display, like trikes with snow tracks, from the 50's to present day, but quite a few of them looked unusual enough for me and junior to stay interested. There wasn't a huge amount of information and it was all in Italian, apart from a few lines in the leaflet, but we managed to figure out a few things. It was just us and a school group when we visited.
Someone had to be dragged out of the office to sell us a souvenir mug but he then happily offered to take photos of us all together on a motorbike that you are allowed to sit on. So after 4 days in Rome the only family photo we have is of us all posed around a motorbike.
Why this place doesn't get a mention in Lonely Planet and the like I do not understand.