The program involved five digital billboards located along key streets around London. The billboards are equipped with camera technology that has been used by police and other government agencies to catch speeders or to monitor for traffic congestion. As used by Castrol, the cameras would read the license plate of a vehicle approaching a billboard and use the registry from the Driver and Vehicle Licensing Agency to determine the type of vehicle.

The billboard would then flash a personalized message indicating the Castrol engine oil prescribed for that model. For example: 1 DF L, the right oil for your car is: Castrol Magnatec 5W-30 A1.

Castrol officials called the billboard initiative an extension of a longer-running campaign that allows individuals to type their license plate onto a website to obtain the same recommendation about which engine oil to use. That service, found at www.castrol.com/uk, also works off make-and-model data.

The lubricant company was clearly enthusiastic about finding a new way to make direct contact with potential customers – a prospect that would make many an advertiser salivate.

Weve enjoyed great success with our text and online registration-plate oil selection service and are very excited about taking it to the roadside, Castrol Marketing Manager Rob Stroud said in a statement issued with the launch of the campaign. Were hoping that the unique method of message delivery will get significant cut-through with drivers to deliver the Right Oil-Right Car message.

But some reaction to the campaign has been less than supportive. Tabloid newspaper The Mail on Sunday published an article with a headline that called the advertisements bizarre. It quoted a member of Parliament complaining that the campaign was an inappropriate use of personal information.

Another news outlet, Just-auto.com, reported Monday that the Driver and Vehicle Licensing Agency launched an investigation in response to a complaint by The Mail on Sunday. The article said DVLA denied providing the database to Castrol. The agency does have a policy of selling the database to organizations such as parking enforcement authorities and has also sold it to five companies that provide data to the motor service industry. The idea behind the latter sales is that it will help ensure that repair shops install correct replacement parts.

The Just-auto.com article quoted unnamed sources disclosing that Castrol obtained the database from an unidentified party that bought it from one of the five motor industry data providers. The article also said that Castrol paid hundreds of thousands of pounds for the information. Castrol refused to discuss the amount that it paid.

Castrol originally intended the billboard campaign to be a two-week trial, but halted it after only four days. The company noted that the campaign included steps to ensure that Castrol employees did not view information such as names of vehicle owners. It also said that it considered its use of the information to be consistent with that envisioned by DVLA, but added that it would await the outcome of the agencys investigation before deciding whether to resume the campaign.

We believed the trial was entirely in line with the service provided by our data supplier, said Chris Sedgewick, marketing director for Castrol UK and Ireland. However, we immediately ceased the interactive trial pending a review as we would never compromise the DVLAs data.