The driver’s window of the average car does a lot more work than any of the other power windows on board. What can happen over time is that the tracks the window glass runs in become clogged with dust and debris or simply go dry, meaning there’s excess friction when the glass is trying to change position. Thanks to gravity, this is usually most often seen when trying to raise the glass.

You can try a dry lubricant spray which typically contains graphite to grease the tracks slightly, but don’t overdo it. And try to avoid liquid lubricants as these will smear the glass. If that doesn’t work, you may have to take the door and glass apart to find the problem. It could also be that the electric motor that does the work of moving the glass is worn and not providing the necessary power.

In the meantime, you can help the motor by grabbing the top of the glass and using a little elbow grease to help it make the journey. Just make sure you don’t get your fingers in the way as the window shuts.

The short answer: No. The 2005 Camry four-cylinder was rated to tow only 1200kg (with trailer brakes fitted). Even the three-litre V6 version of the Camry was rated to 1600kg.

So, even with the caravan you’ve nominated absolutely empty (no water, luggage or food supplies on board) it would still be way over the Camry’s limit. Ignoring these limits leaves you open to all sorts of potential legal and insurance hassles should something go wrong. You also stand to damage the towing vehicle by overloading it. Fundamentally, you need either a bigger car or a smaller caravan.

With a limited budget like yours I would suggest to go for a car with a good reliability record. While the Mercedes-Benz is a good car you are likely to be facing an expensive repair if anything should go wrong. Consider a Mitsubishi 380 or a Toyota Camry of around 2000-2003.