There are aftermarket reversing cameras that you can buy online (though, few are Bluetooth connected, perhaps because it can be a bit of an unstable connection) — but we haven't tested any recently as many of them require wiring through the rear light cluster in order to fit a camera onto the rear of the car (usually above the reg plate or nearby). The best thing to do is look online and if you find one you like the look of and it's in budget, check what warranty they offer and if they have a customer service team in case anything goes wrong. Similarly, it's a good idea to look at the customer reviews and the company's score on Trustpilot.

Many of the options you'll see are cheaper units from overseas, which tend to have very little customer support — which is why it's worth looking at the customer reviews. In that sense, I'd probably buy via Halfords or the like. This one is well-reviewed and would probably be my pick (though, I only looked briefly): www.halfords.com/technology/reversing-cameras/echo...l