Paul Walker's Extraordinary act of kindness revealed & why ''he was happier than he had ever been'' when he died

It's no secret that the cast of the Fast & Furious franchise was extremely close, as was reflected in the on-screen chemistry that helped make the action series so successful.

This, too, is what no doubt accounts for making this Paul Walker tribute video, which the franchise released on its official YouTube channel Wednesday, so affecting.

Set the "Coming Home" by P.Diddy, and running slightly more than two minutes, the video is neither maudlin nor overwrought. It's simple, artful and genuine – which is exactly why it's the perfect tribute to Walker.

Almost 10 years later, Kyle and Kristen Upham are still bowled over by Paul Walker's unbelievable generosity – after he changed their lives with a single gesture.

The couple were shopping for an engagement ring in a Santa Barbara, Calif., jewelry store in 2004, when Walker overheard them talking about a gorgeous ring – one they couldn't afford, reports CBS Los Angeles. The couple, from Victorville, ultimately left the store without a ring - after they decided they could not afford the $9,000 diamond band that Mrs Upham had set her heart on.
A short time later, a sales assistant called the couple and told them to return to the store - where they were presented with the ring. 
Walker had sought out the manager of the store and told him to put the ring 'on his tab'.
When they astounded couple asked who bought it for them, the clerks refused to say - at Walker's request.
The Uphams kept the gift receipt and often suspected it had been the star but could never be certain.
The store, which has since closed its Santa Barbara outlet, kept Walker's secret but after the 40-year-old's tragic death in a car crash on Saturday, employee Irene King felt the world should know the actor's true character.
Mrs Upham said Walker's gesture remains the kindness thing anyone had ever done for her.

Walker bought the $9,000 ring for them, then slipped away without a word.

"It's still to this day the most generous thing anyone has ever done for me," Kristen says today.

They were never 100 percent sure it was Walker, though they had chatted with him in the store. This week, after Walker's tragic death in a car wreck, their suspicions were confirmed after clerk at the jewelry store spoke up.

"To do something like that to a perfect stranger is just unbelievable," the clerk, Irene King, says.

Kyle Upham was preparing for a second tour in Iraq at the time. "When [Walker] found out Kyle just came back from Iraq – I remember seeing the look in his face," Kristen says. "He kind of transformed."

"When we hand down the ring through the generations, there will always be a story to tell," Kyle says.

Adds Kristen: "His real life speaks volumes of his character. He really did put his money where his mouth is, and did good for this world."

Paul with his 15year old daughter Meadow

He may have been a movie star, but friends say the role Paul Walker cherished most was Dad.

At the time of his tragic death on Saturday, the actor was living with daughter Meadow, 15, full time and loving every minute as an involved father.

"He told me recently he was the happiest he'd ever been," close friend Brandon Birtell tells PEOPLE. "It was directly because of the growing relationship with his daughter and the clarity that brought to his life."

In her younger years, Meadow lived in Hawaii with her mother, and Walker’s one time girlfriend, Rebecca Soteros. His own schedule meant constant travel from his California home base, but Walker's little girl was never far from his heart.

"It really affected him that he missed time with her in her early years because he was working," Walker's longtime manager and close friend Matt Luber tells PEOPLE. "It was a struggle for him. [When she moved to California], he wanted to make the most of every single moment with her. He was completely dedicated."

In fact, despite the fact that the free-spirited Walker "liked the freedom of having no roots, she was the only thing he couldn't stand being away from,” adds Birtell.

Paul Walker's grief-stricken girlfriend appeared in public Tuesday for the first time since the fiery car wreck that cost the actor his life.  It has emerged that when Pilchard-Gosnell learned of Walker's death, she alleged collapsed in shock.
Jasmine Pilchard-Gosnell, 23, made an emotional visit to Walker's Santa Barbara home yesterday - just three days after the 40-year-old star of the Fast & Furious franchise was killed along with his friend Roger Rodas in a horrific Porsche crash. The grief-stricken woman wiped her eyes while standing barefoot outside her car and engulfed in tears.
The young woman appeared visibly shaken as she spent three hours at the house with her late boyfriend’s family. 

Paul Walker:'' I would like to think  I was a nice guy''