About the only tax implications I could see.... If the car is a company owned asset, and has been depreciated over the last 3-5 years. The car is then sold back to VW...... There would be a taxable event for the difference between the buyback amount and unamortized balance of the asset (the car in this case).From the long form
"While it is the intention of the parties that any payments made as a result of the Class Action Settlement not be subject to taxation, you should consult a tax professional to assess the specific tax implications of any payment you may receive. For example, if you have used your vehicle for business purposes, previously claimed a depreciation deduction on your vehicle, or receive an amount that exceeds the cost of your vehicle, some or all of your payment may be subject to taxation. "
On a personal level, I don't believe there is a threshold unless I am missing something. People don't take depreciation on a personal auto. If the car is being bought back for more than somebody has paid for the car.... In that case I would check with a tax person. Even on that level I would imagine you could then deduct the operating costs (taxes, interest, insurance, etc...) I can't see a scenario where one would pay.
Another mitigating factor could be if VW 1099's the owners who buy back. As long as you sell back for less than what you paid, you should be OK. There is no true "gain" if you get back less than what you paid for it.