The Mini Clubman may be the iconic era-defining car of the Swinging Sixties, but it was the Austin 1100 which was the speedy, reliable compact car of choice for less groovy folk across the country.

It is April 1983 and I am in a yellow Austin 1100 with my father on the M4 heading west into thrashing rain. The 20-year-old wipers creek and groan and intermittently attempt to fight off the incoming storm, like the Spartans at Thermopylae, or Luke and Han faced with legions of stormtroopers when trying to blast their way out of the Death Star.

We are in this small leaky car because I am a man in love. My little obsessive 12-year-old brain is fixated with an Australian actress called Janet Fielding, or more precisely, with Tegan Jovanka, the sexy air hostess she plays in Doctor Who.

Always in the Tardis dressed in her lilac flight attendant gear, with a cute matching fez that she rests on the side of her head, French-beret style, she has triggered a prepubescent lust in me that I struggle to contain. The Tom Baker and Peter Davison Doctor Whos were my obsession, my escape, my every second thought, and Tegan was my pin-up girl.

I have heard that Janet Fielding will be at a Doctor Who convention in Longleat, near Bath... answering questions! Signing autographs! Looking gorgeous! I ask my father if we can go and, of course, he says yes. However, my father has no job, and has had a breakdown; we have no money; and he has sold both our cars just to have some cash to live on. We are in a bungalow in Weybridge that we all hate, and our belongings remain unpacked in boxes in the dining room. For the first time in his adult life he has no car, the object that defines and expresses him most.

Late at night I hear my parents strategising about the Longleat trip; now and then a voice is raised, then shushed. We can't go to Longleat without a car, it's as simple as that, and I begin to lose hope that I will ever meet Tegan.

Then one morning on the driveway there is a yellow Austin 1100, with its bonnet up and my father buried deep inside the engine, trying to breathe fire into it. I can hear him curse as the machine will not start. There are greasy, oily rags littering the driveway, along with cans of various mechanical lubricants and potions intended to inspire the internal combustion engine to ignite. Spark plugs are checked, changed; the exhaust pipe removed, examined, cleaned, replaced. At one point, with the car up on a jack, he disappears underneath the chassis on a small homemade tray with wheels, a wrench in his hand.

As uninterested in cars as ever, I return to my fantasy world and leave my father to attempt his motor-mechanic alchemy on this rusting bone-shaker. After a while there is a BANG, a whizzing sound and a yelp of glee. I can hear an engine gently purring. I look out my window and see my father, with crazed Einstein hair, topless, covered in grease, smoking a small cigar, gazing at the car, a slight smile of triumph on his lips. It is the first time I've seen him smile in a long time.

I stand the other side of the trestle table to the seated Tegan Jovanka. I am unable to speak, dumbstruck by the Australian vision in front of me. She smiles that Tegan smile and hands me a photo of herself that she has just signed personally for me... 'To Grant... love from Janet Fielding', with three kisses and an exclamation mark. I stare deep into her lovely hazel eyes and I feel a warmth and terror that is utterly new to me. Tegan smiles professionally back, and tells me cheerily to "keep watching". I hear my father thanking her for making my day then he gently nudges me to move on as there is a queue of hundreds of other boys (and a few much older men who should know better) queuing for some Tegan-love.

Within weeks of this trip my father had turned his life around, found a new job and money, and we had moved to a house that we loved. I changed schools, and soon my father could afford a new car. He traded in his now souped-up Austin 1100 for a second-hand white Ford Escort.

Thank you, Tegan, thank you, Janet. My infatuation with you pushed my father, gave him the momentum he needed to create a new life for us all. Making that car start was his own Doctor Who-like regeneration from one man into another. He regained his self-respect, and I got to meet the space-travelling woman of my dreams.