Lotus could have been a much stronger force in the 2015 Formula 1 season had it not been hindered by financial issues, according to technical director Nick Chester.
The team struggled financially during the year and its car suffered from a lack of development as a consequence.
Romain Grosjean still managed a podium in the second half of the season and Lotus is currently in sixth place in the standings.
Chester admits the lack of development has been frustrating.
"I was pleased with the car in a lot of ways but disappointed in the amount of development," said Chester.
"We made a good basic car that handled well and with which the drivers could extract the maximum from.
"Unfortunately we have not been able to put developments on it due to finances; we could have gone a lot further with it otherwise and that would have been very interesting to see."
Deputy team principal Federico Gastaldi agreed with Chester's view that Lotus could have achieve much more without its financial problems.
"We aimed for fifth in the constructors' championship and stayed in the fight most of the season despite the year's constraints," he said.
"Had things turned out differently, we had the car and the people to take us there – and even further up the order - no problem."
New business model needed
Gastaldi also called for changes to the Formula 1 business model, saying it is difficult to see where the sport is heading if things continue like up until now.
"I believe it is crucial for Formula 1 to review its business model," he added. "There are so many financial issues throughout the sport, whether for teams or promoters, that it is hard to see where things will go.
"I know that both Mr. Ecclestone and the FIA have been trying to change things and I also know that teams aren't always the easiest to work with when we have to join forces.
"Our agendas and situations differ too much and are almost always preceded with self-preservation.
"Additionally, and I have said this before, we have to do everything that we can – all of us – to help promoters sell tickets. Without fans, where would we be?"