Alternately, where the name of a car can hardly be 'removed', the manufacturer is thanked in the end, I cannot but think that not only was the car donated (who gets possession of it afterwards - that is if the A-team did not smash it up in the first place?) but perhaps also an advertising fee was negotiated.
My invariable idea is then that names of any equipment noticably displayed, probably mostly has a history of money behind it rather than outright class (not insinuating anything regarding the names shown).
Perhaps someone with inside knowledge can broaden my horisons?
Actually they do remove identifying marks from cars if nothing's been negotiated. When you see products with their logos being proudly displayed, they usually appear for one of two reasons. One is more traditional advertising, where the company would pay to have their product displayed in a movie or TV show. The other is as a means of lowering production costs, where the producers would ask to loan the products in exchange for the product placement.
In the case of hif-fi equipment though, I'm pretty sure that's the handywork of the prop master. They source gear from all sorts of places and often, with things the general public isn't too familiar with, pick them for looks rather than considering if the character would have the means to afford them. The Meridians are probably just some old, non working pair that someone donated, or it might be simply be a replica, that gets used on various sets.
Films they've appeared in off the top of my head are Shutter, Dinner for Schmucks, Get Him to the Greek, Date Night and I Love You Man, although I think the pair in Get Him to the Greek may in fact be a different pair as I think they were more modern, could easily be promotional consideration that one.
EDIT: Oh yea, Tracy Jordan has a pair of Revel Ultima Studio 2s in 30 Rock.