Robert Kubica feels like a 'passenger' in Williams Formula 1 car

Kubica has battled handling difficulties with his F1 car since the season-opening Australian GP, where he struck a kerb in first practice and damaged the floor.

Williams data suggested Kubica's repaired car was displaying different aerodynamic behaviour despite running the same set-up as rookie team-mate George Russell in Bahrain.

Kubica's pace fell away badly in the second half of the race as his tyres degraded, after strong opening stint where he got ahead of his team-mate.

"Until now it's like I have to make sure I actually turn into the corner and don't spin, and then this is my driving - everything focused on this," said Kubica, who described his Bahrain race as a "survival" after finishing two laps down in 16th.

"We need to find out what's going on because I have no margin and I have no window in the car where actually I can drive it. I am a passenger.

"We need a solution, and this will hopefully take less time than I think.

"When there was more driver-ability [needed] I think I did well.

"I've been eight years not driving [in F1 races], so I think I took good decisions.

"Some things were positive, but it's extremely difficult. Everything is building up - all the difficulties.

"Australia by running over one kerb where everybody took it, I lost pieces of the car. In Bahrain, I stay out of the kerbs. The time in qualifying I use them, another bit flew away.

"And then in the race, actually I realised I'm not using them, or I'm using them only because I was put there, I don't use them as [part of the] track.

"If you start tightening up corners, you put more load on the tyres. It is a complicated situation.

"I was so slow in some corners to try to protect the rear tyres, but I was still sliding and still overheating them.

"There will be a point hopefully one day, when all these limitations, I can forget about it, the car will be more solid, stay all together and it will become more fun as well."

Williams is still short of parts after finishing its new car late and missing part of pre-season testing. Kubica is concerned this will delay solutions for his problem.

"You can do whatever you want - you can put rear tyres on the front! It will be dominated by the characteristics we are having," added Kubica, who was at least happy to gain clearer understanding than after Australia.

"I can only try to help it with the tools - I tried to do everything with the diff settings, with the settings you have on the steering wheel - but it's so big it's impossible to turn it around.

"It [the wind] makes stability of the car even worse and I have no stability already, so this exaggerated [the problem]."