High Ya,
Yes, for sure you can recover full rars. (as long as you have enough pars)
Try to get as much as possible first - makes recovery faster.
In newreaders proberly use right click & download as incompletes, or something similar
info 4 newbies:
Parity Volumes may be used to verify that a set of files have
not been corrupted, or to reconstruct damaged files.
Damaged files can be repaired.
To get the most benefit from the use of PAR2, it is important
that everyone ensure that they download incomplete files.
A single byte error in a 10MB file might only require the use
of recovery data from a PAR file that is only 100KB in size.
PAR2 Utilities:
Windows
http://www.quickpar.org.uk/
Unix/Linux
http://parchive.sourceforge.net/
Mac OSX
http://www.xs4all.nl/~gp/MacPAR_deLuxe/