Officers on patrol in Acocks Green on Saturday were approached by a woman who had taken a photo of the driver.
They continued their rounds and stopped the suspect minutes later after spotting him behind the wheel of a car near Fox Hollies Road.
He failed to provide identification and, suspecting he may have been in the country illegally, made checks at his home address in Solihull where they uncovered a bag containing around £25,000 in cash.
West Midlands Police recovered the money while financial investigators in the Economic Crime Unit conduct enquiries.
If the man cannot prove he has come about the money legally they will look to permanently seize it under the Proceeds of Crime Act (POCA).
A 25-year-old man was charged with possessing an offensive weapon – it’s alleged he was carrying a lock knife in his pocket – and is due to appear in Birmingham Magistrates Court on January 28.
Officers will also be passing details across to immigration officials who will look into his status in the UK.