Our friends at Popular Mechanics have put together a list of what they consider the top ten most influential crashes in NASCAR history, complete with video. These ten smash-ups were influential not in how they changed the course of a single race, but in how they got us to today's "Car of Tomorrow," a race car that is to "stock car" what the Republican Party is to "conservatives." That is to say, it's become nothing at all like a real for-sale car, and therefore not-at-all interesting to most hardcore gearheads. But maybe we all just need a reminder of how the "sport" got to be where it is today. Popular Mechanics has put together this list, with video clips, of ten big wrecks that provoked change in NASCAR.
10.) Let's See How The CoT And This Here New Soft Wall Hold Up

A 2008 crash at Texas that proved to be the biggest test yet for the CoT and the new safer walls. Somehow Michael McDowell survived.
9.) Bristol Will Always Be A Car-Basher

Two clips, 12 years apart, show that Bristol will always have an appetite for destruction, no matter what changes you make.
8.) Biggest Wreck Ever

After this happened at Daytona in 1960, NASCAR realized that they had unleashed a whole new beast with their super-speedway. This may only rank eighth on the PopMech list, but it's our favorite. You just can't beat the combination of old jalopies, the ol'-timey-voiced commentary, and primitive "safety" precautions.
7.) The King Demands Window Nets

After "The King" Richard Petty's body flopped around out of his window during this crash in 1970, NASCAR decided that it was time to dictate the use of window nets. Long live The King.
6.) Why We Have Roof Flaps

These two clips show two big flippin' crahses by Rusty Wallace during the 1993 season, which eventually led to the creation of roof flaps that pop-up when the car is sliding backwards. They create downforce to keep the car planted on the ground and prevent cars from catching big X-Games-style air.
5.) Why We Now Have Pit Road Speed Limits

Mike Ritch was tragically killed when Ricky Rudd's car spun out of control in pit lane. To help prevent this from happening again, new pit lane speed limits were introduced.
4.) Why We Have Restrictor Plates

200MPH+ may be spectacular to watch, but there's no getting around the added danger of higher speeds. But isn't that the point of motorsport? To go as fast as possible, safety be damned? Well, no matter how we see it, NASCAR decided after this crash that something had to be done to reduce speeds.
3.) Fireball Roberts

A tragically ironic end to his life, Fireball Roberts died just the way his nickname implied. Fire-retardant safety gear took a step up after this, but the sport was never the same without his charisma.
2.) Rubbin' Is Racin'

The famous tangle up between Donnie Allison and Cale Yarborough on network TV ensured that NASCAR would be prime entertainment fixture for years to come. We wish more drivers would get in fistfights nowadays.
1.) Yup, You Guessed It

The crash that will live in infamy.