one more useful 'egg' way:
1. get the biggest syringe you can find with thickest needle
2. slightly smash a few eggs with a mixer and fill the syringe with it
3. now be a doctor for a while
Make several 'injections' into car seats in different places, also dont forget doors and floor, all fabrics, etc...
4. 3-4 days passed - and the smell is awesome! they will need to throw away the whole seats and carpets...
...and the pierced places are almost invisible, so they won't notice anything until it rot
I tested this recipe personally - it really works! that bastard is still tearing hair on his ass (2 years already)