Mr Brennan was a customer of Webster's Autocentre in March 2019 on the day that Tyrone Dobbs's grandmother Evelyn Plummer had started work there under duress. She had been arrested in Paris for refusing to pay his fare and Tyrone had been forced to pay her €700 fine. To pay him back, he told her he was now employed by him. What he didn't tell her was that part of her duties including car valeting but it came in useful when Mr Brennan arrived and complained that they were late in finishing his car and demanded a reduction in his bill. He said that he'd been forced to leave his wife, heavily pregnant with twins, bathing their elder son herself and as a result he demanded it be rounded down from £126 to £100. Evelyn called him over, saying she had just been about to ring his wife to say that the car was ready, and to return the pair of knickers she had found down the back seat, which were obviously too small a size for an expectant mother. Mr Brennan recognised subtle blackmail when he saw it and not only paid the bill in full but also booked in for an expensive premier service and full valet on 3rd April.
- Credited as "Customer", the character's name was given in dialogue.