But Bob will have to deposit this dirty cash at some point. With enough cash, it’ll raise alarm bells unless Beth has A LOT of friends who can deposit $600 each.
Often it's more for tax evasion. Beth pays for cars as a business expense.
Bob just happens to have the Cayman Islands as the business location.
Money flows from U.S. business as a deductible expense, to the location out of the IRS's reach.
Or there isn't one Beth but lots of people with dodgy credit cards from banks in weird places. Those card holders indeed get their money in suitcases full of folding money, pay for their "rentals" and so the money flows into legitimate commerce. Bob of course pays for this.
> Bob will have to deposit this dirty cash at some point
This is a layering mechanism, designed to obfuscate and distribute dirty cash. There may be many Bobs. Or Bob may be fine running cash to Mexico whereas Beth is not; this lets Bob sell that service to Beth.
(I’m also not sure how much Turo requires rentals be settled through its platform. If it allows off-platform billing and settling, there is no need to reimburse with dirty cash.)
The whole point of money laundering is to get criminal money into the banking system. Once it’s in the banking system you’re done. That’s why strip clubs and other cash heavy businesses are used to mix it all in.
Or Bob knows people who know what to do with suitcases full of $500 Euro notes without alerting legal issues.
Presumably Beth pays Bob for this service.
Then Bob may have to pay his friends.
This can be done with varying degrees of sophistication.