What a car business
should spend.

A common rule of thumb is to spend a set share of revenue on marketing. For car businesses it falls apart fast. A $55,000 new SUV and a $9,000 used hatch can carry similar dollar margins, or the hatch can carry more. A workshop's revenue is a mix of labour and parts with different margins again. A percentage of turnover tells you how big the business is, not what you can afford to pay for one more sale.

Gross profit is the honest starting point. For a dealer that's typically the front-end margin on the car plus what finance, insurance and accessories add. For a workshop it's labour and parts margin over a year of visits. You know these numbers better than any agency does.

The maths is three steps. First, the most you'll pay for one sale: gross profit times the share you're willing to spend. Second, the most you'll pay for one enquiry: that figure divided by how many enquiries it takes to make a sale. Third, the budget: cost per sale times the extra sales you want.

A made-up example. A used car yard in Wyong makes $3,000 gross on an average car and is happy to spend 15% of that, so it can pay up to $450 per car sold. If one in eight enquiries buys, it can pay about $56 per enquiry. Ten extra cars a month means a budget of about $4,500 across every channel, listing fees included.

Pick dealer or workshop and put in your own numbers. The starting figures are made up. It runs in your browser and nothing is sent anywhere.

A first service at $280 can look like it doesn't justify a $90 ad cost. But a customer who likes you comes back at every service interval, for tyres, brakes and the odd surprise, and in NSW most cars over five years old need a yearly safety inspection. Value them on what a kept customer is worth over a year or two, and the sums change.

There's a lot of customer to win. The head of the Australian Automotive Aftermarket Association told CHOICE that Australia has nearly 20 million vehicles on the road, and half are under warranty, and a 2026 survey for the same association found 44% of owners think they have to service at the dealer to keep it. Workshops that answer that belief plainly are competing for customers who are paying more than they need to.

For most dealers the biggest line isn't Google or Meta. It's listing fees. In carsales' 2026 report, car comparison sites influenced the research of 51% of buyers, so most yards pay to be there. Count those fees in your cost per sale like any other channel, then compare. The split below is a typical starting shape, not a rule.

• Dealers: listing sites first, then Google search and vehicle ads for stock and brand, then Facebook and Instagram to bring back people who looked.
• Workshops: Google Business Profile and reviews cost time, not money, so start there. Then search ads for the jobs you want more of.
• Tyre, detailing and panel shops: search ads for the job and suburb, and photos of your own work on social.
• Everyone: hold back a slice to test one new thing each quarter, and judge it on sales.

Google treats your daily budget as an average. On a busy day a campaign can spend up to twice it, and across the month it won't go past 30.4 times it, as Google's budget help page explains. So a $50 daily budget can spend $100 on a Saturday and still land at about $1,520 for the month. That's normal, not a fault.

Meta works in weeks. Jon Loomer, who tracks Meta's ad changes closely, reports that ad sets can now spend up to 75% over the daily budget on some days, capped at seven times it across a week, and that the change was still rolling out. Set budgets you're comfortable seeing on a big day, and judge them over a month.