Sydney residents who cannot afford to buy their ideal home may be investing in luxury cars as a status symbol. 

Sales of high-end prestige vehicles are accelerating, with the number of Porsches on NSW roads near-doubling in the past five years.

Dr David Waller, senior marketing lecturer at University of Technology Sydney, said luxury brands of all types were becoming "incredibly popular".

Waller said younger people put off by the price of housing in Sydney may be putting more emphasis on the sort of car they drive.

"Units and housing have all gone up," he said.

"Your house reflects who you are - if they can't afford that then the car would reflect who they are.

"A car is so much a status symbol, it's not just metal, tyres and glass – it's what it means to people. Having a luxury brand, particularly something like a Porsche is reward for yourself."

As is the case with real estate, Mr Waller said some high-end cars on Sydney roads may be owned by foreign investors who choose to spend money away from home.

"If they can't show wealth in China they are willing to show it in Australia," he said.

"Some may even see that it shows who they are in being prosperous."

Statistics obtained by Drive show the number of Porsches that call NSW home accelerated from 6781 to 11,933 vehicles between 2012 and 2017 as motorists increasingly turn toward luxury cars. 

Mossman accountant Simon Allsop bought a $411,800 Porsche 911 Turbo Cabriolet in 2016.

"I've always been into cars and really enjoy it," Mr Allsop says.

"I can do the school pick-up with the kids and also take it to the race track and be one of the fastest cars there. It's a fantastic combination of practicality and performance."

Mr Allsop, 35, said Sydney's prestige car clique is growing on the back of public events such as Cars and Coffee and the Bullrush Rally, where "people appreciate the cars rather than loathing the cars, which I guess is an Australian characteristic".

"The tall poppy thing has hindered growth historically here," he said.

"[But] I've found the car scene a fantastic place to network and meet other small business owners."

Porsche has moved from selling an average of 115 cars per month in 2007 to 458 cars in Australia this year, helped by the popularity of its Macan and Cayenne SUVs.

The German brand isn't alone in its growth. Ferrari marked a local record by selling more than 100 cars in the first six months of 2017 and McLaren is set to rack up best-ever figures in Australia this year.

Mercedes-Benz grew from 61,000 cars and SUVs on NSW roads in 2007 to around 112,000 vehicles today, doubling its presence in a decade.

Setting SUVs and dual-cab utes aside, Mercedes-Benz sells more passenger cars in Australia than Ford, Honda, Subaru, Nissan or Mitsubishi.