@b-tone : Sure CSM can't read them, it's the reverse side of the medal for flexibility of partial saving : i got to completely redesign .car format, sorry.
@PSVWally : Another guy told me about this matter with Download Accelerator, i don't know what happens with that tool, well, anyhow, an easy solution exist : just right-clic on the package icon and choose "save as..." and it will be good. Hopefully my tools are not heavy enough to need a download manager.
Just for info, Flashget works perfectly right.