According to Mythbusters, the potato would have flown right out of Brimmer's car exhaust and it would have started without any trouble. Of course, there are any number of ways Columbo could have disabled his vehicle, ala Butterfly in Shades of Gray.

Joe

Thanks! It's nice to know I'm entertaining you with my English English

As for your suggestion about the lens, I admit that it makes more sense
that way: It's what I assumed at first! But when I watched again, I was sure
Columbo inferred that the lens Brimmer found was in the boot only by some strange
coincidence!

Mythbusters is a good show.........but I am going to pretend I never saw your post Joe I just love that whole scene with Columbo walking off with Kennicut and he says...."ya take a potata..."

Your point is well taken Kev-La. The only thing I will say is that I think Columbo was being a little coy here. When he tells Kennicut that it wasn't Lenore's lens, Kennicut asks him who's was it, and Columbo answers who knows....what really matters is Brimmers actions...going there that night and trying to get rid of the lens. Columbo's coyness in not admitting to planting the lens is also seen when Kennicut asks him what he would have done if the car had started, and adds that Columbo couldn't have set up "this trap". Well Columbo never directly answers his question but he refers to his childhood prank of the "potata" in the exhaust pipe.
Now why else would Columbo disable the car if he hadn't planted the lens and was waiting for Brimmer to come and incriminate himself.

One thing I always found amusing is that Brimmer tries to say he was looking for papers. Well, I don't know about you, but if I was looking for papers in my trunk/boot I really don't think I would need to climb all the way in there to look for them!!

I'm sure you're right about that - it
certainly all seems to fit together.
That cheeky Lieutenant really is a cad, isn't he?

It is just my take on it....I could be wrong.