VirtualBox Guest Additions on Fedora 20/19, CentOS/RHEL 6.5/5.10

This link helps
Make sure to read the comments for updated help..
Above link if you like to copy and paste links
http://www.if-not-true-then-false.com/2010/install-virtualbox-guest-additions-on-fedora-centos-red-hat-rhel

Also see
http://wiki.centos.org/HowTos/Virtualization/VirtualBox/CentOSguest

http://wiki.centos.org/FAQ/CentOS6#head-012846a4e422267a34e81c4c905654fc8f36ffaf

 My suggestion from the comments above

I had to use the info that brandon posted above
ln -s /usr/src/kernels/2.6.32-431.3.1.el6.x86_64/ /usr/src/kernels/2.6.32-431.el6.x86_64
it does not like the extra kernel info 3.1.
and the fix from

http://wiki.centos.org/HowTos/Virtualization/VirtualBox/CentOSguest

Patch for CentOS 6.5 with VBOXADDITIONS_4.3.2/4.3.4
cd /usr/src/kernels//include/drm/
ln -s /usr/include/drm/drm.h drm.h
ln -s /usr/include/drm/drm_sarea.h drm_sarea.h
ln -s /usr/include/drm/drm_mode.h drm_mode.h
ln -s /usr/include/drm/drm_fourcc.h drm_fourcc.h

which is linked from https://forums.virtualbox.org/viewtopic.php?f=3&t=58855