should i buy copyright for using real car names and models in my game?

While IANAL, and I cannot give you any solid legal reply (and getting that may be very difficult or next to impossible, given different national laws), I can give you some advise from my experience when I wrote the racing game Redline, and some more random thoughts.

-We tried to find out the legal license requirements for using cars in games as well, and never found any authoritative answer.

-It appears that some licensing is required at least in some jurisdictions, as all the major car game titles I found will state in some text that cars brands a licensed.

-On the other hand, I don't quite understand the reasoning behind requiring licenses for cars in games. Take a look at movies for example. I doubt that you need to get a license for every single car seen in the background of a movie. Why should games be any different.

-Licenses may be hard or expensive or impossible to get. I know that some car manufacturers have (or had in the past) exclusive deals with some game makers. Which is for example why you never saw in Ferraris or Porsches in Sony's Gran Turismo (that may have changed, haven't played any recent versions of the game), because, i believe EA had an exclusive license.

-There is always the option to take cars which people recognize, but not to explicitly state brand names or logo. We chose to go that way for Redline. Grand Theft Auto, for example, does the same.

-Redline has several hundred third-party plugin cars available for download on the internet, most of which are using real car brands, and nobody ever got into any trouble for that. However, nobody is making any money of those.

-When your game is not very high profile, I think it is highly likely that you would get away with using unlicensed real cars without anyone noticing/caring. Since you are doing an online game (web player), it is easy to remove infringing licenses should somebody complain. Note that I am not advocating trademark infringement here - I am pointing this out, because the actual legal situation of this is very difficult to figure out, and doing this may very well be actually legal in your country (also see the movie analogy).

'how much is the pricing', well if you have to ask then its too much ;)

Licenses are there to protect their IP and control when/how its used, not necessarily as a simple legal way to incorporate their IP into someones game. Unless you are approached by one of the manufactures to create a game around their brand or are producing a high profile, respected game I seriously doubt they will be interested.

If you use copyrighted car names, manufacture names and recognisable models of a car, you need a license, failure to do so and if your game is noticed will likely result in a 'cease and desist' letter, regardless of whether the game is commercial or given away for free. The companies have to do this in order to maintain their control of the copyright/ip.

In some cases it may be possible to come to an agreement to use the likeness of assets or a brand name/logo, but those are few and far between.

Save yourself the hassle and just invent cars, names, manufactures.

I was looking into this today. I found this legal judgement on a man making Batmobile replicas for sale. Obviously, he loses but the document covers some US law on what constitutes copyrights on cars.

"Defendant repeatedly argues that the Batmobile is only a car and that the design of a car is not protectable under copyright law, citing to the House Report. "

Here is the link: http://www.hollywoodreporter.com/sites/default/files/custom/Documents/ESQ/batmobile.pdf

I found it with a Google search "what are copyrights on batmobile"

It is a 2013 Judgement so it is fairly current.