For anyone who thought Grease and mods were a thing of the past, check out this collection of bad-boy looks -- doubters will be biting their tongues in no time.

Grease continues to influence contemporary fashion with leather jackets and slicked-back hair still going strong. Beware, ladies: things could get steamy when flipping through these pics. For anyone looking for more subtle badass qualities, options such as brass-knuckle umbrellas or even booze belts are sure to help with the cool factor without the risk of turning into John Travolta. These bad-boy looks are sure to provide inspiration for the upcoming fashion season.

Implications - These bad-boy looks take the popularity of fashion from times gone by and revive them to appeal to the modern public. Contemporary consumers appreciate products with a retro feel, as this induces feelings of nostalgia.