HOMESTEAD, Fla. – When NASCAR initially set a 2021 deadline for launching its NextGen car, Toyota Racing Development president David Wilson was skeptical of the timeframe.

Nearly a year later, he believes NASCAR’s overhaul is on track for next season, but he still has reservations about the aggressive rollout of a project that he compares with one of the most ambitious undertakings of the 20th century.

“We need another year, really,” Wilson told NBCSports.com last week about the release of the new car. “Because here’s my concern: We can’t afford to get this wrong. But the analogy is when NASA is doing a moon shot or rocket launch, that’s pretty well thought out, and they’re not afraid to pull the date back. What we’re doing in a relative sense feels like the same thing.

“There’s going to be more change in a year than this sport has seen in the past 60 years combined. Cumulative. It’s a revolutionary change. We as an industry need to get this right.”

During his annual address of the news media Sunday at Homestead-Miami Speedway, NASCAR president Steve Phelps reaffirmed multiple times that the Next Gen is on pace for a 2021 debut.

A prototype of the car recently made its debut at Richmond Raceway with Austin Dillon (whose Richard Childress Racing team worked with NASCAR to build the prototype), but Cup teams likely won’t take delivery on a real-world version to test until next July.

Using a Request For Proposal-type process, NASCAR is soliciting bids on suppliers for the various stock elements that the new car will have, principally the chassis (in a structure that will resemble how Dallara supplies IndyCar teams with a standard chassis).

“The car is on schedule,” Phelps said. “I have to give a shoutout to, again, really the entire industry because they’re working collaboratively. NASCAR runs the process, but there are teams that are involved, (manufacturers) that are involved, and that’s how we’re going to be successful moving forward.”

Multiple people familiar with the Next Gen process but who spoke on the condition of anonymity because they weren’t authorized to speak publicly told NBCSports.com that there are at least three companies being considered seriously to build the chassis.

That list includes Joe Gibbs Racing, which is one of multiple Cup teams that inquired about bidding on the chassis.

It isn’t unusual for a Cup team to build chassis for others (such as Hendrick Motorsports, Roush Fenway Racing and JGR) have counted rivals as clients. But it would be new to have a single team that builds chassis for the entire field.

Phelps mostly demurred when asked by NBCSports.com how NASCAR would handle that arrangement.

“With respect to those that are in the RFPs to build the car, I don’t want to get into specifics about where that is,” Phelps said. “There would obviously need to be a separation between that race team and whatever part or the vehicle itself that’s being put together.

“If there is a team that is interested in competing for what that’s going to be, it would have to be kind of removed from what that organization is.”

Wilson said TRD favors Cup teams getting involved in the business of building the new car because of their familiarity with the output.

“It’s kind of polarizing because of the perceived advantage for the team that’s supplying, but the reason I say that it works to our favor is because nobody understands like a team does what it means to make a quality part,” he said.

Goodyear’s move from a 15- to 18-inch wheel with the new car also will need to be factored into the timeline of the rollout. Goodyear’s Greg Stucker said Thursday morning on SiriusXM NASCAR’s The Morning Drive that it’ll be a “significant change,” but that the tire supplier is on schedule with NASCAR and teams.

Ford Performance global director Mark Rushbrook said nearly 10 months ago that he was optimistic about having the new car by 2021 and reiterated his enthusiasm in a Saturday news conference with manufacturer executives hosted by NASCAR.

“It’s a very exciting time for NASCAR,” Rushbrook said. “To see all the technology and architecture changes that are going into Next Gen, it’s had a very successful test already. I think the fans are going to be excited once they see the final versions of the car. And then leading beyond ’21 to further technology with hybrid I think is important for all of us as manufacturers.”

The commonality of the new car should eliminate the assembly lines that many teams have and result in cost savings (in part by trimming staff). That theoretically should lower the barrier of entry to NASCAR for new teams and manufacturers (NASCAR courted a prospective automaker two weeks ago in Phoenix, according to Phelps).

Ed Laukes, group vice president of marketing for Toyota Motor North America, said the cost reductions were “overdue and had to happen, so one way or another there needs to be new blood brought into the sport, new team ownership brought into the sport, and this is the way that it’s going to happen. I think the vision of (NASCAR chairman) Jim France and of NASCAR right now was very, very appropriate.”

The new car also will enhance showroom relevance with the addition of independent rear suspension.

“When you see the proportions of this car, it fits the production vehicle even better, particularly in the rear,” said Jim Campbell, U.S. vice president of performance and motorsports for Chevrolet. “It matches up to where the Camaro is, and we’re really quite excited about that. Finally, we’ve got symmetry between left‑ and right‑hand side. We needed that so it looks more like the street car. We’ll have a wheel that really mirrors a little bit closer to what you see on the production side in terms of size.”

Phelps said NASCAR has another test of the new car in a few weeks, and Toyota had a Next Gen body in a wind tunnel last week for the second time.

“I handicapped the possibility of racing in ’21 (with the Next Gen car) as a very slim chance,” Wilson said. “I have to eat a little crow. It is on the calendar as they laid out. On paper, it certainly looks like ’21, and certainly Jim France has not given one inch to hedging that.

“I will say that everything has to go to that schedule. There’s no margin for slipping.”

Wilson also believes there needs to be more than one vendor available for some parts to safeguard against unforeseen emergencies and faulty manufacturing.

“I was talking to Steve O’Donnell and Jim France at Charlotte just kind of cautioning them relative to the slippery slope that you have with a single-source supplier,” Wilson said. “Anecdotally, we used to have one valve-spring supplier, and that bit us in the butt. Now we have two. The issue there is very pragmatic, in case say you have a fire that takes out your factory. But the other side is you have a bad batch of material or something that puts you in a tough spot, and you don’t have a backup.

“So just suggesting that they use some, not common sense per se, but that they think about contingencies relative to the supply of parts and pieces.”

Wilson also believes a backup is needed for keeping the 2020 cars in place just in case NASCAR is unable to hit the 2021 target.

But he added the financial straits that many teams are facing have made the ’21 deadline a necessary reality for the NASCAR industry.

“We all know there are teams on the precipice of failing. So there is a lot of pressure,” Wilson said. “We appreciate and respect that there are parts of our sport that are in trouble.

“The team ownership model is nuts. So it’s not that we shouldn’t be attempting (the Next Gen in ’21). But we just need to get it right. If we can’t — hand on heart — make that target in ’21, we need to be prepared with a contingency plan.”