But recently, regulators have put the spotlight on something else to look out for: the "upselling" of various types of insurance known as "add on insurance".

This is where the car dealer might suggest that for a few extra dollars a week, why not take out insurance so that your car loan repayments are protected if you get sick?

Or the bank teller might suggest a policy that claims to cover your credit card repayments if you lose your job.

These types of insurance may sound relevant in the heat of the moment. But the corporate watchdog believes there's a significant risk the cover could be of little use because these policies are often expensive, they duplicate other policies, or it is difficult to make a claim.

For example, QBE in August announced $15.9 million in refunds for more than 35,000 customers who bought add-on insurance through car dealers, because the cover was of "little or no benefit" to consumers.

So, how have car dealers managed to sell so much insurance customers didn't need?

A big part of the answer is that we're more likely to agree to financial products like this when we're also making a bigger financial commitment.

Businesses can exploit this, and the Australian Securities and Investments Commission this month identified some of the common sales tricks car dealers used to do exactly that.

One such tactic is to exploit "decision fatigue," by only mentioning the add-on insurance after you've already made an exhausting series of choices.

Buying a car can involve all manner of decisions such as the brand, make, colour, features, and financing, which can leave you overwhelmed. Studies show that when we're bamboozled with choices, we're more likely to just agree to something to end the process. So we might be more inclined to just agree to the insurance to get out of there.

It's also common to be offered a financial extra, like insurance, after you've agreed to the purchase.

ASIC called this "priming" - you've been primed to buy the insurance because by that stage, you've made the emotional investment to buy the car itself. A study in the United Kingdom found that offering add-on insurance as the car was being sold, rather than earlier, meant consumers would pay more for the insurance.

But surely after a big-ticket outlay like a car, we'd more cautious about handing over even more of our money on complex insurance?

Well, not necessarily.

Behavioural economists point out that when we're deciding on an appropriate price for a product, we compare it with some other reference point, something known as "anchoring". When the reference point is a car that has cost many thousands of dollars, a few hundred dollars more for insurance can seem reasonable enough.

And of course, there's the widely used marketing technique of expressing the cost of something in dollars per week, rather than over a year.

ASIC said it was common for some insurers to only give the price in dollars a week, and not present the final premium until the contract was being signed.

All these techniques are used to promote sales, and to capitalise on quirks in our behaviour that stop many people being purely rational when deciding whether to part with their cash.

They don't always mean the product is a dud. But they are particularly concerning when they're being used to sell something like complex insurance that is poorly understood by its customers and often poor value.

To lower the risk of consumers being dudded, ASIC is proposing a "deferred sales" model which would prohibit businesses from selling add-on insurance at car yards at the same time as they're selling cars.

Bank tellers will also stop selling add-on insurance to customers when they are applying for credit cards.

But if you find these tricks being used on you, it's worth thinking carefully about whether you really need the product.

Twitter: @ClancyYeates