Unknown anime for the pre-school audience

Back in the day, Canal Panda aired shows in 30-minute slots. In between each show, we were treated to see short cartoons that were used to fill during commercial breaks. Now all they have to fill breaks are songs for sissies like Cow... songs that would take someone to Sissyville. In Chicken's words, "that's for babies".
Now the channel has shorter slots, still airs Doraemon (in Portuguese) and 80% of the channel's schedule is aimed at a pre-school audience. However...
Back in 2005, around March or so, one of the shorts that aired on the channel was an anime. That anime was aimed at a pre-school audience. It's not a shortform series based on Anpanman, but this:
-the anime featured anthropomorphic cars, predating Cars by a few years;
-the show was already made in widescreen, it was letterboxed;
-it was dubbed into Portuguese;
-the length was 3-5 mins./episode;
-finally, there was an episode which explained the origin of these cars and that they lived in a toy garage or car park.
I need your help to identify this anime. I haven't seen it in nine years, at least.

A few warnings

Hi. Most of you are warned that this blog will center on personal experiences of mine with cartoons that have since stopped airing on any channel I know. Inspired by Desenhos Animados Esquecidos, I decided to launch an English-speaking version of it because there needs to be a demand. Or maybe not.
Anyway, the point of this blog is to write about cartoons that have the following characteristics:
-Little to no content may exist
-Little to no information about the dub may exist
-This cartoon exists in other languages but the Portuguese dub is a holy grail
-No dubbing information exists
Welcome to Forgotten Cartoons.