They've obviously been there a fair while, given the musty smell and staining along the fold lines so I have to wonder if the previous owner even put them there or if they'd always been in the car since he bought it 2 years ago. I know the "proper" thing to do would be to contact him and ask if he's lost any cash recently, but to be honest I think the onus is on the seller to properly empty the car of anything they wish to keep before sale. At least, if I left 60 quid in a motor I sold, I'd consider it lost and put down to experience...
If you've bought a car recently, or even a long while ago, be sure to check every possible place for hidden prizes like this. Beats the usual couple of 50p's and few pennies you can normally glean from under the seats of a new purchase, along with assorted belly button fluff and fag packet detritus, anyway.
