Comment 28 for bug 1440608

Jarnos, I can confirm that your /etc/kernel/postinst.d/apt-auto-removal and adding the cron job resolves this problem.
I installed the 4.3.0-5-generic kernel and rebooted and then manually purged the 4.3.0-1-generic and it gave some erroneous errors about not being able to find the DKMS modules to delete for that kernel. But after rebooting again there were no dkms modules and the 4.3.0-2-generic and 4.3.0-5-generic are all that are on my system.

Attached is the output of the error messages although the kernel and DKMS modules for 4.3.0-1-generic are confirmed to be gone.