One luxury car importer was offering the free deal on the number plate LH 168, which had previously been priced at $168,800 and translates in Cantonese into 'get wealthy forever', during a car auction over the weekend. It came attached to a new-model Bentley worth nearly $1.7 million.

The radical move by car salesmen and rare-plate traders follows the government's budget initiative to rev up revenue by offering personalised number plates.

Under the scheme, motorists will be able to apply for a personalised number plate with a mix of letters and numbers and a maximum of eight characters.

The plate number applied for then goes to auction and will have a minimum reserve price expected to be 'much higher' than $1,000, according to transport officials.

Some lucky-plate traders fear the new scheme will force them out of business. They have been coming up with eye-catching ploys to offload some of the backlogged stock before the expected December implementation of the plan.

Richburg Motors, a luxury car importer which also trades in lucky plates, was among the first to come up with the novel sales technique.

'We feel disappointed [with the budget initiative] because the combination of the new plate is much more than the old plate with two letters and four numbers,' a spokeswoman said.

'So we expect they will drop a lot on the price ... But at the moment we cannot predict the percentage of the price drop.'

She said they came up with the ploy to offer 'free' lucky number plates because 'so many people are still interested in the lucky plates'.

More than 250 interested buyers turned up at the Hong Kong Convention and Exhibition Centre on Saturday and Sunday for the chance to snap up the freebie that came with the million-dollar-plus motor cars, she said.

The best seller over the weekend was licence plate HK 1816 which was previously marked at $88,800 and given away free with an E-series Mercedes Benz for $899,000.