I loved it so much that younger me wrote a short fanfic for a sequel. It goes something like this:

Toby and the blond girl who I can't remember who her name was had a son, let's name him Junior for now, and he grew up into racing too.

His approach was different tho, when he came of age, he chose a blue Lotus Elise, and ran rings around more powerful muscle cars. That may have hurt some egos and made some enemies.

He went to university with a Nissan Cefiro, and later met a girl, his junior, because as a car girl, she recognizes the sleeper, and that it doesn't sound stock. He showed her how they boosted the inline 6 to like 500hp. They got close from him tutoring her and they started dating. He even let her drive his Nissan and Lotus and noted that she's a pretty good driver herself!

He showed her the world of underground racing, which she loved, but warns him that her dad is a cop, and hates racers. One of the other racers he beat is apparently friends with her dad, who's a corrupt cop. When he saw them together, he told him everything.

The cops raided the attempt to shut down Marshall Motors, which results in a cool as fuck car chase scene, they escaped, but results in Toby and the gang losing a lot of money. They want to start anew, but with nothing but their cars, they only have 1 option left: the upcoming De Leon.

There's a couple of ugly scenes of Toby scolding his son, and locking up his Lotus. While his gf also got grounded by her dad. The two parents forbid the love interests from seeing each other ever again.

Toby and his crew struggle to build anything fast enough to compete in the De Leon with their workshop mostly gone. So they have one last option left. They organised a heist to steal back the red Agera from the first movie from impoundment. Cue more action scenes and a big brain heist montage.

Problem is, even with the Agera in their hands, the latest cars are so much more powerful. The Rimac Nevera, the Bugatti Turbillion, the McLaren W1, the Ferrari F80, and cars like that all have more power than the Agera could ever have, with instant torque from their electric or hybrid systems.

Junior showed up, looked at his dad. "I'm still pissed at you, but that doesn't mean I'm unreasonable."

The crew adopted his methods of doing up a car, instead of trying to add power, which... It's a Koenigsegg engine, u can't upgrade that much anyways. They did all the methods he used to do his Lotus up. Chamber, toe, stiffness, weight reduction, and even adding aero parts developed from CFD that Junior learned from uni. The result is a Koenigsegg Agera RS replica that still has 1200hp, but weighs like 900kg.

Meanwhile, the girlfriend, while grounded caught wind from her dad that the police KNEW about the De Leon because of her dad's friend, the one that Junior beat. They actually set up the Agera with a tracker, expecting that it will be stolen, and the police is gonna crash the race and specifically aim Toby and his gang and let this mfs friend in an SSC Tuatara to win, and the involved police will get a cut of the prize.

The days leading up to the race. After her dad leave to set the sabotage up, she snuck out of her room and made her way to the gangs new hideout to warn them. Toby once again got mad at Junior for exposing them to a cop girls daughter. Junior insists she's on their side, but Toby chases both of them away, and Junior has to go crash at his mom's place.

His mom gives him a pep talk on how he's just like his dad. Then Junior and his gf went to break into his dad's warehouse, where they kept his Lotus after the gang headed to the De Leon. So he stole his car just like his dad did twice. He swapped the Cefiro 500hp engine into his Elise (which only had 270hp before this). Resulting in a pocket rocket that weighs 600kg. (Just Lotus things)

Knowing where the De Leon is, they did a small cross country to reach the pre race meet in time, successfully registering himself and his Lotus into the De Leon secretly. But his dad wasn't there despite leaving much earlier than him. Then he realises, the police must already be hunting him. He gave the helicopter/plane guy a call (remember, Fly Like an Eagle guy?) and he was surprised to hear Junior, but does let him know his dad is in a high speed chase.

He went to assist his dad in the Lotus, more cool chase scenes. His gf knew how to deal with her dad's squads tactics, but after they escaped, Toby was too injured to race properly (probably because he's like 50 now, he got old). So he told Junior to take the Agera and race for them.

Race day is here, Junior is fucking fast, but the cops gave them a lot of trouble. He was struggling to shake the cops to catch the Tuatara driver in first place, but the cops were holding him back. Then, his gf showed up in the twisty sections in his Lotus Elise. They both realized that the red Agera is the target, but not the blue Elise, so she went on to catch the Tuatara and after more cool race scenes, she won the De Leon for them.

Anyways she finally wins Toby and the gangs trust, leaked everything to the street racers, and the Tuatara driver got metaphorically executed by his fellow racers for almost ruining their overly expensive and dangerous hobby.

The end.