Before our road trip to Wales, I speculate what type of driver Rob Brydon might be. Comedians tend to fall into two distinct motoring camps: unworldly, dysfunctional non-drivers (David Mitchell, Arthur Smith, and, until recently, Paul Merton) or tawdry petrol heads (Steve Coogan, Jimmy Carr, Rowan Atkinson).

I’d read that Brydon briefly held the Top Gear “star in the reasonably priced car” lap record – toppled by Simon Cowell – and parked outside his house in Strawberry Hill, West London, is a sleek, grey Audi A4 convertible. So I brace myself for a tail-gating, wheel-thumping ride up the M4.

In fact, Rob Brydon drives like your dad. He is a two chevrons apart, solid 70mph, middle lane-hugger, who frets whether timber is about to blow off a passing HGV. The first leg of our journey is a quest for a special brand of oil for the Audi, necessitating service stops at both Heston and Leigh Delamere. The engine is not, at this juncture, remotely low, but Brydon, cautious, sensible, a bit of a worrywart, cannot relax until he is adequately provisioned.

Not many celebrities with comedy awards, a Bafta nomination, starring roles in movies such as A Cock and Bull Story and a new hit series, Gavin & Stacey, would agree to chauffeur a journalist all the way from London to Porthcawl. “But the thought of driving you to Wales is fine,” he says, as we pass Reading. “You know where you are in a car. I’ve got my music, a bit of money [he gestures to his dashboard loose change pot], my phone, something to eat [his wife Claire has packed us a picnic] and now I’ve got my oil!” For our ten-hour round trip he is warm, generous and amusing company. Only rarely do I detect a status-anxious voice in his head nagging: “I bet Coogan wouldn’t have to do this.”

Brydon’s most famous comic creation also felt most secure within the carapace of his car. Keith Barret, the doleful, Welsh minicab-driving, estranged father in Marion and Geoff, the series that made Brydon famous in 2000, delivered his monologues waiting behind the wheel, a bit early to visit his sons – “my little smashers” – or having driven back from trying to waylay them at Disneyland Paris, still clutching the Tigger and Eeyore toys he was forbidden to give them. It is Keith’s cheery, misplaced optimism – “I didn’t lose a wife,” he says of his cuckolding, “so much as gain a friend in Geoff” – which wrings dark humour from this raw and rejected love.

Anyhow, Brydon is happy to visit his home nation, having just made a BBC documentary, Rob Brydon’s Identity Crisis, concerning his mixed feelings about being Welsh. In the process, he says, he has fallen back in love with the land he once pilloried so mercilessly that his oldest friend David Williams switched off the TV, disgusted that Brydon had “sold his soul to the cynical English middle classes”.

To my own cynical English ears Brydon’s old stand-up material about Wales – when he toured in his Keith Barret persona – is hardly searing. In mock innocence he asks a Welsh-speaker in the audience, “Oh, so do you find it a useful language, then… when you’re travelling around Europe?” He quips that while the Scots say defiantly, “The English can take our land, but they’ll never have our freedom,” the Welsh say, “You’ve taken our land, don’t forget our freedom before you go. Thanks for coming! Oh, they were a lovely invading force…”

Rather, Williams’ reaction begs the old question: why are the Welsh so humourless about themselves? When Anne Robinson shoved the whole nation into Room 101 or writer A.A. Gill described them as “ugly pugnacious little trolls” or when Brydon himself, asked where he’d take a girl for a date in Wales, replied “from behind”, each provoked boot-faced outrage from Plaid Cymru, even wittering from the Welsh Select Committee.

It is an issue Brydon addresses in his film, consulting Welsh academics and celebrities such as Max Boyce and Griff Rhys Jones. He concludes that Wales suffers from low self-esteem. A ballsier, less insecure nation would quip back or rise above the affront. But Wales has previously defined itself too much in relation to its hated neighbour and only now, with devolution and the Welsh language enjoying a renaissance, is it starting to relax about what others think.

As we proceed Welshwards at a strictly legal pace, the springlike London weather regresses to mid-winter. Brydon, despondent, offers a biscuit, but when I reach for the sole Toffee Crisp, snaps: “Biscuit, Janice, not confectionery! You can have it only if you say, ‘He was strangely alluring, better looking than on TV.’” Actually, in person Brydon is a magnetic balance of physical pros and cons. His 5ft 7in stature is offset by a sexy, small-man energy (hints of his hero Bruce Springsteen), his lugubrious goat-skull head by his rich, baritone voice.

Brydon was born and raised around Baglan, near Port Talbot, by a school teacher mother and car dealer father who educated him privately until he was 14. He was always a good boy, never rebellious, liked by teachers, though unacademic. But he had a talent, a magic voice, he could make everyone laugh with impressions of teachers or Elvis or the Muppets. His parents passed on an appreciation of comedy: they loved Barry Humphries, Pete and Dud, the Two Ronnies. He recalls proudly finding himself at a party chatting with Corbett and Humphries about the vagaries of corporate gigs. I guffaw at the odd comedy trio and he frowns. “I know Ronnie, he’s a friend,” he says. “He and Anne came to my show in Edinburgh.”

The refreshing thing about Brydon is he has no interest in being cool. He always preferred Dud to Pete, Corbett to Barker, the warm, cuddly comic to the colder genius. Corbett was one of two star guests at his 40th birthday: the other was Shakin’ Stevens. (Brydon’s musical taste, as I discover on the return journey, is hopelessly naff.) He does a burst of Ronnie Corbett for me, a voice you cannot hear without smiling. Steve Coogan’s Ronnie, he says, is better, but these days he won’t do impressions. “Now he’s had his teeth fixed and made it big in America?” I snipe. Brydon bristles. He feels honour-bound to defend any comic, even one he doesn’t know or even like, even Jimmy Carr. “No, I think Steve has just entertained enough people; he doesn’t need to do it any more.”

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