"Death Proof" is Quentin Tarantino's half of the Grindhouse double feature (other half: "Planet Terror" by Robert Rodgriguez), a hommage to exploitation movies and B-movies of the 50s to the 70s.
As such, Quentin Tarantino made a movie that has everything what makes an exploitation film an exploitation film: filthy optic, bad cutting, a lack of story and - of course - violence and sex.
Exploitation movies are movies that are supposed to be cheap, but make a lot of fun with their silliness and Quentin Tarantino made exactly what is the definition of an exploitation movie.
And as such, the movie works pretty well - even though it is not as great as his other movies.
Contains spoilers:
There is an INCREDIBLE amount of sexual and strong language is heard throughout the movie.
No sexual activity is shown except for one lapdance scene, but it is more like something you see in a Pussycat Dolls music video.
There is drug and alcohol use, mostly in the first episode.
The violence, however, is extreme:
A woman is trapped in a car and a man makes the car jump so the woman's head is repeatenly smashed against the window. She is later seen completely bloody. She dies.
The same man willingly crashes into a car full of women, one person is thrown out of the car (nothing gory shown), a woman's leg is severed and falls onto the road (it is very dark and shadow-ish but it seen clearly - the severing part is quick, but the part where it falls down is long - some blood)
A moving wheel quickly drives over a woman's face (brief and dark, but it is gruesome)
After this moment - it is in the middle of the movie - the violence is not THAT strong. Some women beat up a man to death and it is depicted glorifying, though not too strong.
I had jump when the scene came with the jumping car and many other young people will find this movie extremely frightning and disturbing. This is not a real horror movie and the violence is infrequent, but i doubt all teenagers will be able to handle this movie.
But about the drug use and the very strong language - know your child.