When I was in Cartagena I saw several "used car lots" simular to the "tote the note lots" here in the US. So there must be the same in Barq. Service didn't seem high on the list of priorities and I saw very few "real" repair shops, and service is probably beyond the means of most Colombians, so they likely do almost everthing at home, by themselves on an emergency basis.
As far as cost, there is quite a large tax on impotered cars, it used to be 100%
HD