Listen. I read some of the other reviews and this is what I have to say - this is not a home vacuum cleaner that runs on 220V AC. Its a tiny car unit that runs on 12V DC. Adjust your expectations.
You'll have to work it. It does the job but requires you to be involved a little more than a home vacuum cleaner. This particular unit lacks a lot of necessary attachments that could have allowed you to reach the tighter spaces and little crevices in your car but nonetheless, its a good unit for basic car cleanliness. The motor is powerful enough (again, adjust your expectations), and the build quality is great.
One hack to get maximum power out of it is to keep your car on and running. Don't use it on your car's standby battery power. Not only will you avoid the risk of a dead battery, but you'll also notice a boost in power.