Volkswagen CEO Herbert Diess is worried about Tesla’s lead in self-driving and software.

In an internal Volkswagen e-mail that leaked this past weekend, Diess discussed Tesla’s impressive system for improving its vehicle’s self-driving capability. Diess seemed to admit that Tesla’s full self-driving infrastructure is far superior to any other mainstream automaker today.

Diess said:

“What worries me the most is the capabilities in the assistance systems. 500,000 Teslas function as a neural network that continuously collects data and provides the customer a new driving experience every 14 days with improved properties. No other automobile manufacturer can do that today.”

Diess also spoke about Tesla’s software, which is arguably the best in the market today. The CEO stated that Tesla’s system for updating vehicles and providing drivers with new experiences is “continuous.” Interestingly enough, software is something that Volkswagen is having difficulty with in its ID.3 electric cars.

The leak was obtained by German car magazine Automobilwoche on Saturday, April 25.

This is not the first time Volkswagen has admitted Tesla’s lead in the EV segment. Volkswagen has previously stated that Tesla holds a sizable lead in the electric transportation sector. In mid-March, Volkswagen board member Thomas Ulbrich said that the Silicon Valley-based electric carmaker held a ten-year lead in the industry. “Tesla is an impressive manufacturer. It is a motivator for us. Tesla has ten years more experience. But we are very quick in catching up,” Ulbrich said.

However, there is mutual respect between the two automakers. It is evident based on comments from both company’s CEOs.

Herbert Diess and Elon Musk have shown genuine respect for each other for a long time. Diess has always been very respectful to Musk, crediting him for bringing the electric vehicle infrastructure to the mainstream and providing consumers with an environmentally friendly option for transportation.

At the Golden Steering Wheel Awards in November 2019, Musk and Diess traded complements with each other. After the Tesla Model 3 took home an award at the event, Diess congratulated Musk and recognized his attempts to bring the world away from environmentally-harming transportation.

“First of all, I really wanted to congratulate you, great achievement, I know all of this competition here in Germany, this award, its a great achievement. We know each other; we don’t meet so often, though. I would say that we share a vision, which is that we only can achieve the CO2 targets and reduce carbon emissions through electric cars,” Diess said.

Volkswagen has a tainted past due to the Dieselgate scandal, which revealed that the German automaker was placing cheat devices in its vehicles to pass standard emissions testing. However, the company has made many attempts to clear its name, and Diess is undoubtedly a big part of that.

In the past, Volkswagen has outlined its $33 billion plan to begin a transition to electrification. The German automaker certainly seems to plan to put its emissions scandal in the past, and Diess maintains that Musk is a big reason for its decision to move toward more sustainable vehicles. “I thank you for pioneering, for pulling us, for pushing us. I think really Elon is the innovator, which is driving us along,” Diess said.