The American manufacturer finished as the top LMDh finisher with its new V-Series.R, two laps behind the dominant Toyota Le Mans Hypercars that finished 1-2 but just 10 seconds behind the third-placed Ferrari 499P LMH.
Lynn and team-mates Earl Bamber and Richard Westbrook finished another two laps ahead of both of the Porsche 963s despite Lynn picking up a drive-through penalty in the second hour for not respecting the full-course yellow procedure.
The British driver said that Cadillac can't be disappointed to miss out on the bottom step of the podium to Ferrari.
"No doubt it’s a strong and positive day for Cadillac Racing," commented Lynn. "We started our WEC campaign with a fourth place and I think we would have taken that at the start of the weekend.
"This is the first time everyone has worked together on a brand-new program, and to come within 10 seconds of a podium against a team as strong as Ferrari is just a fantastic start with so much more to improve on.
"We’re a team that wants to achieve good things, so whilst we respect it as a good result we come away feeling like we wanted more.”
Bamber completed almost half of the race distance in the Chip Ganassi Racing-run #2 machine, and was at the wheel for the closing stages as he gave chase to the pole-winning #50 Ferrari.
"We were fighting for a podium with the Ferrari and a little bit unlucky with a full-course yellow at the end," said the New Zealander. "We were sort of best of the rest, so we’re going to push on.
"The team did a fantastic job first time in LMDh and it’s on to Portimao for the next race.”
Westbrook added: "I’m just very proud of everyone. We stayed out of trouble and on another day we could have gotten third.
"We’re only going to go forward now. We got so much data now to go through. It’s just so invaluable. It beats any eight-hour test.”
General Motors sportscar racing programe manager Laura Wontrop Klauser expressed her satisfaction with Cadillac's performance on its WEC debut, which followed the V-Series.R's race debut in the IMSA WeatherTech SportsCar Championship-opening Rolex 24 at Daytona in January.
“In 2022, the development of this car, the testing schedule, everything that we went through was so tough on the team, but we are seeing the results and we are so proud of all that work and effort that we put in. It was worth it,” said Klauser.
“We have a solid car and we can’t wait to get to the rest of the WEC season and the IMSA season and show the world how great it is.
“Every time we turn the car on we learn something. Whether if we move it or even if it sits still, we learn something and the racing is the best way possible to learn. So we can only grow and get better.”
