Even though rain was an unwelcome sight on Wednesday morning, the GP2 teams participating in this week's two day post-season GP2 test session at the Circuit of Catalunya just outside of Barcelona, Spain said their time on track had been productive both in analysing car set-ups and evaluating the performances of possible driver signings for 2013.

Even though they're exiting GP2 after the 2012 season, Scuderia Coloni still not only turned up and participated in the session, but came away with the fastest times in both the morning and afternoon sessions on Tuesday. Luca Filippi's morning time proved to be the fastest lap of the entire two-day test after Wednesday was hit by heavy rain in the morning that left the track drying well into the afternoon.

"I'm very proud for the results scored by my drivers in this test," said team principal Paolo Coloni. "Even though we are set to leave this championship at the end of the year, we proved that we are one of the top teams in the series and our drivers can aim at the front end of the charts.

"The talent and the skills of Luca were never under discussion in 2011, when he ended up as the series runner-up in the second part of the season, he added. "The same goes for this season, when he went back to victory in just two races and scored the pole at Singapore."

Testing with his new 2013 team Rapax, former Coloni driver Stefano Coletti was also happy with the work achieved at Barcelona, despite the inclement weather on Wednesday and not getting a chance to try setting any fast laps on new tyres because of a late red flag.

"We ended the test with the sixth absolute time which is quite positive as it was obtained on worn tyres," the Monaco-born driver explained. "The test of Barcelona turned out to be very fruitful: we did not seek the single lap performance and focused instead on trying several solutions out."

"Obviously some of them were interesting, some others were not but it was important to complete the scheduled programme as the GP2 Series does not allow very many testing chances during the season," he added.

Caterham Racing's Alexander Rossi finished fastest in the Wednesday afternoon test session. He admitted that it had taken him some time the previous day to get used to the GP2-model cars after his season competing in the World Series by Renault championship.

"I spent the morning adjusting my driving style to suit the GP2 car, which reacts to input much differently than a World Series car," he explained. "It was great to get back in the GP2 car and work with the Caterham Racing team again. Having raced here a few weeks ago, I know my way around Barcelona."

Racing Engineering opted to test a spread of drivers at Barcelona, with Brazil's Andr? Negr?o and Canada's Gianmarco Raimondo running on Tuesday, and then Nigel Melker from the Netherlands and Facundo Regalia from Argentina getting behind the wheel on the Wednesday.

"With Andr? Negr?o and Gianmarco Raimondo we had two rookies in the cars on day 1," explained Thomas Couyotopoulo, the sporting director of Racing Engineering. "It was good to see how quickly they adapted to the GP2 car and its peculiarities. The Pirelli tyres were an additional challenge for Andre and Gianmarco and we were pleased to see how well they managed them.

"Day 2 was, even though heavily influenced by the rain in the morning, a very productive day as well," he continued. Referring to GP2 regular Melker as a "consistent presence" for the team allowing them to benchmark the performance of the other three drivers, he said the Dutchman had "done a good job throughout the day, setting the 4th fastest time in the morning and finishing 3rd in the afternoon even though he encountered some traffic on each of his fast laps. He has shown a strong and stable performance.

"Facundo Regalia, on his second day in a GP2 car, set the fastest lap time in the morning session on a wet track," added Couyotopoulo. "This is a very positive result for him and underlines the performance of our car. In the afternoon Facundo continued adapting to the GP2 car and made another step in his performance from the previous day."

Trident Racing meanwhile opted to run Julian Leal on both days, while Marcus Ericsson and St?phane Richelmi took turns in the team's second car. Leal and Richelmi both drove for the team full time in 2012, but Ericsson was new to Trident having spent the past season with iSport.

"With Ericsson, who was at his first time working with Trident Racing, we tried to go for a fast lap and we succeeded, with some great laptimes," explained the team's managing director Luca Zerbini. "In the PM session Marcus clocked the second fastest lap and mastered the car in just a few time. We've been following him for a while and he's very talented.

"With Leal and Richelmi, who drove the car in 2012, we brought on-track some new technical solutions," he continued. "Both drivers were just perfect as they worked in direct contact with the team's technical staff and followed the advice of the engineers."

Zerbini was already looking forward to the second and final post-season test of the year, to be held at Jerez in three weeks time.

"We will continue the same type of work at Jerez with Julian, who will run in both days, and St?phane, who will join us during the first day," said Zerbini. "It seems incredible that after years of racing with this car there are still areas to investigate, but there are so many variables that every single day of testing can be key to verify the job done."