First, you should create a form using Contact Form 7 plugin, then you can use shortcode to add form into any places you wish.

[contact-form-7 404 "Not Found"]

Pictures

 
Plymouth Roadrunner 10 Plymouth Roadrunner 19 1967 Cougar 1970 Challenger 1971 Pontiac Formula 400 1971 Pontiac Formula 400 1971 Pontiac Formula 400 1965 Mustang Coupe- OCD Customs 1965 Mustang Coupe- OCD Customs 1965 Mustang Coupe- OCD Customs