Convertibles offer a unique experience that no other type of automobile can replicate. With mother nature as your hairstylist and over 90 million miles of headroom, open-air driving gives an unrivaled sense of freedom. Many automakers have capitalized on this, offering convertible versions of popular models. Some have taken this idea one step further and offer certain vehicles as only convertibles.

Occasionally, however, a carmaker misses the boat. Not just any boat, but a cruise ship docked in the harbor, friends, and family on deck screaming at you to climb aboard. So, inexplicably, some models were never available as a convertible. Instead, buyers were stuck with a roof as inflexible as the company that designed it.

This problem has existed for decades. Though certainly not the earliest example, the Dodge Challenger has never been available as a convertible, except a few ultra-rare examples from the 1970s. Meanwhile, a substantial portion of contemporary Mustangs and Camaros are soft-tops. The Toyota GT86 and Subaru BR-Z twins were almost Miata competitors, except the Miata can let its professionally dressed hair down. Then there’s the FJ Cruiser, which — in typical Toyota fashion — was a more reliable alternative to a Jeep, but also a boring one, as its fixed-roof diminished its fun factor.

A few manufacturers suffer from the opposite problem. Some have created drop-tops out of vehicles that no reasonable person would ever want to be seen driving. In the early 2000s, you could buy a two-door convertible version of the Toyota RAV4, the Chevy Tracker, and the Land Rover Freelander. These failed, so in 2011 Nissan decided to have a go and created the Murano CrossCabriolet. Unfortunately, the only positive aspect of the Nissan Murano CrossCabriolet is the smile it brings to the faces of car enthusiasts who spot them on the road and laugh at them.

Nissan, however, was far from the only automaker to shimmy together an ill-conceived convertible. There was the Toyota Solara convertible, which was about as cool as the surface of Venus. The Lexus SC430 was the last car sold with a cassette tape player — a fact that says everything you need to know about its consumer base. More recently, the Buick Cascada has been as popular as the U2 album that randomly appeared on your iPod.

Has every car that should exist as a convertible been made into one? Definitely not. What’s the next car that should take its hat off?