I am trying to get the list of all car2go cars and use it for a test application, the only problem is I do not know how to get the information. I have gotten a consumer key and secret key but the problem is I am unsure how to get the file using the API and then once I get the file I don't know how I would read it since it is using XML.
The response from the html is on this site http://code.google.com/p/car2go/wiki/vehicles_v2_1
once I get the file I don't know how I would read it since it is using xml
You'll need to parse the response to extract the data you want. There are a number of ways to do that. For example, you could use NSXMLParser (which is included in Cocoa Touch), or you could use the TouchXML library, or you could use libxml.