Sure. Rather than driving the motor with a steady source of DC, drive
it from the amplified-and-filtered output of a Soundblaster 16 FM
synth. It's the only way to get really high-quality wow and flutter.
Using a modern PCI card, or a sample-based wow and flutter inducer,
simply won't give good results.
I would have thought that was fairly obvious. Consider the parts
critical to _avoiding_ wow and flutter.
For the mechanical, pick a part that has a periodicity approximating (or
which is a submultiple of) the effect you want, make it "out of round"
or otherwise askew, off balance, or in frictional contact with something
that will brake it at one or more (in the case of the submultiple)
places, and Bob's yer uncle.
For the electronic, modulate the drive motor. Depending on the sort of
motor the deck uses, that can mean modulating the voltage or frequency.
You could probably get something similar by messing with the tape path.