British Touring Car squad Thorney Motorsport has pulled out of the Thruxton round this weekend.
Thorney suffered handling and engine issues with its NGTC Vauxhall Insignia VXR-R at Donington Park earlier this month, resulting in the team withdrawing the car after qualifying.
It had hoped to compete at Thruxton, but now team boss and lead driver John Thorne has decided to focus on solving the problems ahead of the Oulton Park round in June.
"It is with a heavy heart we have taken this decision but with limited budget we can't afford to both test and race," said Thorne. "And the car has some fundamental issues that we need to address before competing again.
"The handling issues are really just down to time in the car to properly create a full set-up. That needs testing and that needs budget. However the engine issues are really annoying as they date back right to last year."
Thorney plans to spend the next few weeks testing and using other drivers to improve the Insignia before returning.
"The BTCC for us is a long-term commitment so we are looking at this as a regroup and come back out fighting," added Thorne. "Some of the issues are just down to lack of development budget and some are just frustrating as they are outside of our control, but no one said racing was easy so we are a long way from giving up yet."