‘I’ve never been so terrified in my entire life,’ says McClenaghan. ‘I mean, I’ve done rock climbing and hanging off a cliff edge with one finger was nothing to this.’

Five years ago McClenaghan joined Premier Direct as sales and marketing director. It was around this time that he went to a motor-racing event at Bedford Aerodrome. He so liked what he saw that he decided to check out the fastest road car £16,000 can buy – an Ultima GTR.

‘I was taken for a test drive down some country lanes. It was phenomenal. I was simply terrified by this car, and the way it was being driven by quite an elderly man. I was shaking, absolutely white as a sheet, and I just said: “Good God – I’ve got to have one of those!”’

McClenaghan was still shaking after driving home to his wife, who had unwittingly sown the seeds of his obsession by getting him the day’s track permit for the Bedford Aerodrome for his birthday. That said, his passion for cars goes back further.

‘I’ve always, always loved cars and I’ve driven them at inappropriate speeds,’ says McClenaghan, who has collected an average of one speeding ticket a year since the age of 17. ‘I’ve only been banned from driving once, for a fortnight, after going down the M4 at 100 miles an hour because I was late for a plane.’

It’s tough deciding whether McClenaghan can be classed as an adrenalin junkie or simply competitive to the core of his being. In all likelihood, it’s a combustible mixture of the two. Despite being ‘terrified’ by his ride in an Ultima GTR, he decided the car wasn’t fast enough for him: ‘I went to the garage that looks after me with my private car, and gave them a budget to build me the quickest Ultima ever. It took the thick end of a year – and was a very bitter process. The final price was over three times the original budget, part of which I funded, and part of which the garage funded.’

McClenaghan ended up with a ‘phenomenally fast car’ – and a 50 per cent stake in the garage. He notes with glee that his Ultima is ‘lighter and faster’ than the official version, which holds several world records.

‘A day out at the track, as anyone who has done one will know, means driving the car for a maximum of two hours,’ he says. ‘Either the car breaks or, physically, the human being breaks. I don’t know how Formula 1 drivers cope with that G-force and that level of adrenalin for so long.’

This all sounds pretty perilous, but McClenaghan rejects the idea that there’s any genuine danger. ‘The odd person breaks the odd limb. I’ve had one small bump which caused minor damage to the car and major bruising to my ego.’

His wife certainly isn’t concerned. ‘She knows I’ve always been into competitive, adrenalin-fuelled sports. She’s never worried about me ending up dead because she’s pretty confident in my ability.’

At 47 years old, McClenaghan clearly prides himself on having the physical fitness and appetite for thrills of a much younger man. But though his love of racing is undiminished, his work and family commitments are squeezing the time he gets to spend with his car.

‘The tragedy of this story – if there is a tragedy – is that I’ve only got out twice in the whole of this year, so this beautiful racing car is sitting rotting in my garage,’ he says. ‘It’s time to find a new hobby.’

I wonder whether he might pass it on to his 16-year-old son, who’s also into racing. ‘He has no chance,’ McClenaghan replies. ‘We have an old Volkswagon Polo, which will be his first car. He has to learn his craft before he does anything silly like that.’