The collective noun for luxury cars is the same as the collective noun for any type of car, a fleet of luxury cars.
No there are not any cheap luxury cars on the market. There are however, some great quality cars that with many features that you will like at a lower price.
A used luxury car is exactly what it says it is, a used luxury car. It is any luxury car that has already be pre-owned and is up for resale. Mercedes Benz, BMW, and Lexus are examples of Luxury cars that when sold back the manufacturer become used luxury cars.
I am assuming that you are wanting to work at a luxury car dealer. If this is the case, you would have to check your local luxury car rental businesses to see if they have any openings. It would also depend on what you are wanting to do (wash cars, rent cars, etc.).
Many kinds of cars are compatible with convertible tops but mainly they are sports cars, luxury cars and jeeps. Pretty much any cars can be converted into one with a convertible top.
Jaguar is a British luxury brand which now is owned by Indian auto giant Tata. As with any luxury brands, the cars calls for high prices, but they are generally perceived as one of the less well received luxury brands at the current generation of auto makers in 2014.
Used to be luxury cars made in England called "Wolseley"
I believe any non-commercial vehicle over $50,000 or $55,000 in the USA has the tax.
A website that I can suggest to inform you on luxury car prices is any car dealership website. There are many car dealership sites, you just need to find one that have luxury cars.
"No, the Cadillac Catera would be considered a full size sedan due to its rather large size. In fact, Cadiillac does not make any small, or compact cars. They are rather well known for their large luxury cars."
Pretty much any rental car company offers luxury car rental. You just have to specify what you want. I know Enterprise rents luxury cars, so you can just check with them. I'm not sure about any of the other places. Almost all car rental companies have a "luxury" category. Some even have "prestige" or specialty categories. There are companies, like Priority One Auto Rental in Boston,MA that only do luxury. Usually you can get a better selection of cars, and much better service, by going to a company that specializes in this area.
Just about any car you want short of a ultra luxury car.