I can't agree. For one cars as basically all things carry an artistic value and besides that one of applied arts. They can in fact look pretty nice. Not agreeing with the things cars stand for or the damage they cause is one thing (and one that I actually support) but saying all cars are ugly seems a bit of an exaggeration.
I have a sense of beauty informed by my sense of morality. I can't look at something I know is harmful and feel good about its existence. When I look at a car, I see the carbon dioxide and the extinct species it will cause. I see the particulate emission and the children it will give asthma. I see the rage and laziness of the driver, and the potential for a bloody crash with a dead pedestrian. It's ugly.
I'd argue that at least the vast majority of cars are fugly beyond reason. Especially when compared to their surrounding. Maybe once they design a car that doesn't stick out like a sore thumb next to a regular building.
And also solve the inherent ugliness of the filth, ludicrous cost and ever present hint of extremely violent death. Such inelegance can't be beautiful in my eyes. Even the decadent quality is spoiled by the lack of any class.