The "Fast & Furious 7" has finished filming last July and it was a big relief for the whole cast and crew. The untimely death of Paul Walker made it tough for them to finish the film because he is one of the main stars of the film. Thankfully, Cody and Caleb Walker agreed to finish the scenes of their brother. With the help of today's technology, the producer and director tried to make the siblings appear like Paul Walker.

During an interview with Collider, James Wan revealed how tough and fulfilling it was working on "Fast and Furious 7". He said, "The size of the budget doesn't make that much of a difference because the kind of issues I have on a low budget film I have on a big budget film as well, but they're just much bigger. It doesn't matter how big or small your film is, you still don't have enough money. You don't have enough time to shoot it."

James Wan further explained, "When you're making a bigger movie you have much bigger set pieces that require more time and more effort and more people. But Fast 7 is definitely the hardest movie I've had to do in my career. And it's not just me. Neil Moritz [the film's producer] has been doing this for a long time and is a very successful, seasoned producer and he said that to me too. That Fast 7 is the hardest movie he's ever had to make as well in his entire career. And it's very true. But I think the final product will surprise a lot of people."

The director admitted, "It's that hardest film I've ever had to make but it's also the one I'm proudest of. I'm really proud of this film." James Wan wasn't the only one who had a difficult time shooting "Fast & Furious 7". Vin Diesel also revealed the struggles of filming without his best friend Paul Walker.

The actor that stars as Dominic Toretto said in an interview, "I grew up in the bouncer world, and we lost people while we were bouncing. But the brotherhood in Paul Walker was something completely different." He explained, "It was someone that we... we grew up in the business together, and we became famous together, and we represented the biggest franchise together. He was my partner, and it's a strange thing to... I've been acting all my life and they don't teach you in acting, how to mourn someone and simultaneously pretend they're in a scene with you."

Vin Diesel revealed, "It's one of the darker moments in this, in my journey. Yeah. Yeah guys, you know it's a rough one. You all had people you love that passed away."

"Fast & Furious 7" will hit the U.S. theaters on April 3, 2015.