It is Mercedes' "precision and attention to detail" that is behind the team's utter dominance of Formula 1 since 2014.
That is the view of Romain Grosjean, who got an up close and personal look at the championship winning team recently when he attended a seat fitting at Brackley.
Although the French GP date change means his race weekend demo runs were called off, former Haas driver Grosjean will still get a full test at the wheel of last year's Mercedes at Paul Ricard at the end of June.
The test is a gesture from Mercedes so that the Frenchman's last memory of driving a Formula 1 car is not his fiery 2019 crash in Bahrain.
"I will work all day with the car that won the French GP in 2019," Grosjean, who is now an Indycar driver, told Canal Plus.
"This is a great opportunity to find out what a good Formula 1 car should be.
"At Brackley, everything is at the highest level - you can feel it in the atmosphere and culture of the team. I am impressed with the precision and attention to detail.
"I got the chance to test their simulator and realised how far advanced they are."
Grosjean said he has even be surprised by how open Mercedes was during his visit.
"The team opened every door for me, explained how every switch on the steering wheel worked. I was happy and even surprised by this approach.
"Actually I am amazed at their openness. They told me everything. They said 'We will try everything. Everything will be like a race weekend'," Grosjean said.
Meanwhile, Grosjean gave his view about last weekend's Monaco GP, which was derided as processional and boring by so many observers.
"As everyone knows, there are two scenarios in Monaco," he said. "Either something is constantly happening, or everything drags on for a very long time.
"It's sad that Charles Leclerc couldn't start the race - it broke my heart," Grosjean added. "But then we saw Verstappen's masterclass.
"It was an extremely unsuccessful race for Mercedes, but that rarely happens to them."
