American driver Conor Daly - son of Irish former F1 and Champ Car driver Derek Daly - finally got to impress the GP2 paddock on Thursday afternoon, after two previous days had been hit by poor weather.

Daly was called up for test duty at short notice by Hilmer Motorsport, a new German team about to embark on its first year in the GP2 Series and which currently has no confirmed drivers for the forthcoming season, which starts in two weeks time at the Sepang International Circuit in Malaysia on March 22-24.

"This was totally unexpected," said Daly. "I was in England and within a day the deal was talked about by The KINC agency and I was on a plane."

Working alongside Pal Varhaug on Tuesday and Italian Formula Three champion Riccardo Agostini on the Wednesday, Daly proved to be the fastest Hilmer driver in all four sessions, but the difficult wet weather conditions meant that there was little opportunity for him to shine and really make a mark for himself.

Daly had only been signed up for two of the three days at Barcelona, which meant that he was set to lose out on the chance of a day of dry track conditions on the Thursday - until another last-minute deal called him back to duty for the final afternoon session, taking over from Agostini.

"This afternoon was crazy," he said. "I had just three hours to learn the dry line and the car's ability at full tilt."

But it had definitely been a very worthwhile experience for him. "The car was amazing on the soft tyres at the end," he said. He managed to just slip into the top ten in the final timings, with a lap of 1:30.417 on the 2.892-mile, 16-turn Spanish circuit. He felt he could have gone even better if he'd just been a bit more fortunate with his flying lap.

"The soft tyres are good for just one lap and as has happened so many times, I got caught in traffic at the hairpin and lost half a second," said Daly. "Not to worry, this week has been amazing for me as it was totally unexpected. The team did a great job helping me understand what GP2 cars can do."

Hilmer Motorsport was also happy with Daly's efforts on their behalf.

"Conor was fantastic," said team owner Franz Hilman, who is also the boss of Formtech GmbH which is a supplier for several F1 teams. "For a rookie who had never driven a GP2 car before to be in the top ten in the rain and dry was impressive.

"We did a lot with him and he had to share the car on the last day which was not ideal, but he did a great job," Hilman added.

The team had already topped the timesheets in their first full GP2 track outing the previous week in pre-season testing at the Circuit de Jerez, thanks to French driver Tom Dillmann. The team is yet to confirm who will drive for them in their maiden GP2 season, and Dillmann spent this latest round of testing working with the even newer Russian Time squad.

As for Daly, it's been a busy few months for the young American driver, who also had his first IZOD IndyCar Series test in December with the AJ Foyt Racing team at Sebring International Raceway in Florida.

However, Daly is expected to spend 2013 back in the GP3 Series in which he has competed for the last two years, first with Carlin in 2011 and then last year moving over to the Lotus GP team with whom he clinched sixth place in the drivers championship.

Daly claimed his first GP3 win in last year's sprint race at Barcelona, along with two second places (in Britain and Germany) and a further two podium positions in 2012, and clearly would like to finish off the job properly by lifting the championship trophy in 2013.

Daly will be back at Barcelona again next week for the second round of GP3 pre-season testing at the Circuit de Catalunya, where he is expected to once again be at the wheel of the ART Grand Prix #1 car. However, Daly's race seat in the 2013 GP3 season has not yet been formally confirmed, and he indicated at the start of the week that he was still waiting for his new race deal to fully come together before anything could be announced.

The question is whether that points to any potential difficulties locking down sponsorship money, or whether it's down to Daly keeping his options open given how fluid the GP2 driver market remains even just two weeks away from the series opener in Malayasia.