i want to put in a new stereo. the factory one is about 7x4 inches, like a double din. can they fit it if i want a single din? would this cost more than just putting in a double din one?
Double din head units are generally more to buy. you can fit a single din head unit with a Console cover plate available from most car Accessories centres or the main dealer.
have a look on the main jvc car audio site for comparisons. it all depends on what you want from your stereo. ie bluetooth, tv screen dvd capability's etc.
this link should give you some ideas. of course you don't necessarily have to go http://www.jvcmobile.co.uk/index1.php?cat=1 for jvc. its just there site is easy to navigate and is quite informative.