Ten-second TV ads and one 30-second spot, created by Biscuit, will launch on 10 January.
They depict humorous characters giving bad advice about how to buy a car. One is posh Petulia, who says that hybrid cars are "totally 'v good' for the Azaleas", while Uncle Barry begins a speech about "choke-based starter systems" of yesteryear.
Meanwhile, the third character, Petrolhead Pete, offers to "well pimp" the viewer's car with matching "chromes".
The ads end by urging viewers to go to Carbuyer.co.uk, which offers reviews and information on deals, for good car advice.
Biscuit was responsible for both the creative and the production. The creative team was Yann Jones and Matt Carter, who was also the director.
The TV ads will run throughout January on ITV and Channel 4 in primetime slots. Print ads are running from today in Dennis publications including Auto Express, Evo, Cyclist and The Week.
Digital activity, including a social media campaign around the hashtags #badforcaradvice and #worstcaradvice, will start from 17 January. The ads will appear on YouTube and 4oD.
The campaign aims to build awareness and web traffic to the site, which launched in October 2010 and claims to receive more than 1.1 million unique users a month.
It is Dennis Publishing’s second biggest website in terms of revenue, with a 50 per cent revenue increase in 2013 compared to 2012, according to Dennis.
Kerry Lee, the marketing director at Carbuyer, said: "Before developing the campaign, we ran several focus groups to find out what our readers wanted and identified how we could improve the content and usability of the site.
"With insights from these and other research, we have updated the site and created a campaign that doesn’t just show its functionality but reflects one of the realities of every-day car buying."
This month the website was updated with a new look and logo. It has more than 40,000 owner reviews.