Hailing as he does from a country whose president is promising to build a wall to keep out the Mexicans, comedian Reginald has his concerns about borders and for a professional funnyman, he was pretty serious about them in this programme.
Perhaps it’s time for that, it’s certainly time to stop laughing when a world leader describes the people from the country next door as being like vermin.
Rather than dwelling on the terrible Mr Trump too long, Reginald’s mission was more to prove how false the idea of borders always was, using music as his launchpoint.
In El Paso, Texas, he met up with a band who played a kind of Mexican music called cumbia that was, itself, not Mexican.
It had come from Colombia, combining African drums with the flutes of the indigenous Indians.
Crossing again into Lone Star, Texas, it had taken on a new form and probably had several others in its future.
Elsewhere in the state, cajunto music cobbled in the polka rhythms and accordion sounds of German settlers, creating a tradition that was neither one thing or another, a little bit oompah and a little bit sombrero but certainly not done justice by labels such as Latin or Mexican or even Tex-Mex.
Even town planners made the point in their own way.
In California there’s a place called Calexia, and symmetrically opposite over the border in Mexico, a twin town called Mexical.
California, Reg discovered, had the first border fence in 1909, but its purpose was just to stop Mexican cows from wandering over.
That might be the only kind of fence that makes sense.
Just after we took the motorway exit for home we’d drive past a vast, overgrown roundabout where my dad would always muse about the outlaws hiding out there.
“If there aren’t any, then I bet there’s a dead body or two,” he would say.
I’m not sure where he got this grisly idea but it seems someone else had it too as Unforgotten (ITV) began a third series with a pile of bones under the central reservation of a motorway.
I was wondering how come a bloke digging up the M1 would have had such a keen eye for the shape of a human pelvis, but they explained that pretty swiftly by telling us he used to be a doctor in Iraq.
It unfurled into quite a global story what with the arm bones having a titanium plate that could only have come from Cyprus in the midNineties, narrowing down the trail to one girl who broke an arm on holiday, aged 13, then vanished from her UK home three years later.
With Nicola Walker and Sanjeev Bhaskar as the slightly odd, slightly mismatched (but not too much) cold case detective duo, this series somehow manages to be bleak without ever losing its heart.
As DCI Cassie Stuart (Walker) rallied her troops to start ringing everyone who’d lost a teenaged daughter in the mid-Nineties, a shiver passed through the room.
A montage of the phone calls, harrowing and sad, reminded us what losing someone really means and that solving puzzles is only one part of a murder detective’s job.
