Button qualified his MP4-28 eighth in the rain-affected session in Malaysia, less than a week after struggling home ninth in the dry Australian GP.
Although he found the car difficult in the damp conditions of Q3, Button believes progress has been made.
"To be two tenths off the guy who won last weekend I don't think is too bad," said the 2009 world champion. "It's funny though because these conditions seemed to really work for us until this point.
"I couldn't find a balance in the wet; I struggled with lack of grip at high-speed at the rear, but I'd take that any day of the week for a better car in the dry.
"If you look through qualifying in Q1 and Q2 on dry tyres we were more competitive. Still nowhere near the top but we're more competitive.
"The guys have done a good job of getting everything out of the car at the moment and I think having two cars in the top 10 is great."
Button also believes the car is now better over longer runs.
"I'm much happier in terms of the long-run pace than in Melbourne," he added.
"I'm looking forward to the race and I wasn't really looking forward to the race in Melbourne. I think we have a better race car.
"It's one week from a tough weekend for us and already we've made some small improvements, although the circuit helps with how smooth it is.
"We're doing a lot of work early in sessions to really understand the car, help the development, and to get the best out if it. We're getting there.
"The positive thing is not the wet pace, but the dry pace we have now in qualifying. Hopefully we can carry that through in the race."
Team-mate Sergio Perez believes the number of changes being made makes it difficult for the drivers to maximise the car, but is pleased with the overall progress.
"We are changing so many things on the car," he said. "Basically today I started with a completely new car so it was difficult for me to get the maximum, but we are doing a good job.
"We've still got a long way to go in terms of car development. Having said that, I can see how hard the team is working to improve our car, and it's a really good feeling to be a part of that."
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