Zanardi tests 2001 package in Florida

The former Williams F1 racer took over team-mate Tony Kanaan's car on Wednesday after the Brazilian had completed two days of running in the Hollywood-backed machine.

"I had a lot of fun today," Zanardi told Speedvision. "It's kind of hard to hold myself back because, obviously, I have been out of the car for a year, so I need to work myself back into it. I'm not where I want to be just yet - I have a lot of rust in my joints! I just have to let it come. It'll be fine when we get to Mexico [the first round] - I'll have 10 days of testing under my belt by then."

Zanardi believes Nunn's team can challenge the likes of Ganassi, Team Kool Green and Penske for the title next season.

"It's a young team but it seems like a very good one," he added. "We have a lot of work to do, but I see a lot of enthusiasm and it's just a question of time. I think having two cars will help Morris to steer things in the right direction with more confidence. I think we can get some good results. It's going to be difficult to beat everybody out there but we're certainly going to try."

Zanardi continues testing today (Thursday). Kanaan, meanwhile, said: "It was a very successful two days, almost perfect. As for my new team-mate using my car...I bedded the brakes for him and I scrubbed some tyres too, so he's ready to go. I'm only loaning it to him and I'll be watching every lap. So he had better behave himself!"