weather strip bottom door edge

Guys,
today I found the weather strips ( not to confuse with the door seals !) on my Buick RMW at the bottom door edges in a very poor condition, they are starting to crunch particulary if you try to remove them. They are usually full of dirt inside the fixing groove and if you try to clean it, they are starting to dismantle themselves.

Furthermore, there´s a cover rail on the bottom area of the doors which ist fixed supposedly with plastic brackets, I´m afraid to remove them due to break or destroy the rails and as well to destroy the fixing brackets......Does anyone know if both are still available ? I`m German and for me it´s a way bigger problem as I can´t visit my local dealer.....

Basically I would be heavily interested in sourcing plastic brackets for all kinds of body moldings, if someone knows a source of supply - would be great

Thanks a lot for help !

The place that has the largest line of plastic fasteners is: http://www.wurthusa.com/web/en/website/produkte_1/bodyshop/clip_fastener_assortments/clip_fastener_assortments.php

The bottom trim can be safely removed with an 11mm socket, and a body fastener fork. The pins usually do not break. The part that is most difficult to find is the small grommet that goes in the door/fender. Wurth does have them.

The bottom edge door seals probably are not available new, but check with Hamilton Chevrolet (in the vender section on the impalassforum). I can occasionally get them, and other plastic parts from junkyard cars. They are the same for sedans and wagons (RM sedan rear doors may be longer, but could be cut to fit).

Fred,
very amazing and helpful links as usual from you, really great ! Have to pick a free day to check out what clips I´m going to find from Würth. Hopefully I´ll get them in Germany,   I`m confidential at least!