Online creative, worth a five-figure sum, has been designed by Arc Interactive, a division of communications firm Arc Marketing, and highlights the message 'V5 Logbook. A car's not legit without it'.
The DVLA is tightening vehicle re-licensing procedures next year to prevent stolen vehicles being made 'street legal' before they are sold to unwitting motorists. Currently anyone can apply for a V5 Logbook while buying a tax disc at post offices. From February, this will no longer be permitted.
Most of the web activity will run on autotrader.co.uk. Visitors searching for details on the top 20 fleet cars and high-risk crime vehicles will receive a spoof ad showing that their search for cars might be fruitless without the correct documentation.
Banners, editorial and email advertising are also running on the Auto Trader site.
Craig Morgan, account director at Arc Interactive, said: "The ads will mirror the real ones apart from the V5 message."
A second phase of ads, using a fresh creative, will appear after Christmas.
In addition to the Auto Trader activity, transitional ads will appear on sites including autoexpress.co.uk, carsource.co.uk and jamjar.co.uk.