Is $4,000 enough for spending money in europe ?

Unless you buy alchohol... yes. Thats about 44 dollars a day. Most days, you wont spend that much, some days, you wont spend anything, just don't buy meaningless stuff. By cool, unique soveineers, and your money will go a long way.

Defiantly that is enough, I went in the summer of 2010 to bosnia and Croatia and i had family there also so i didn't need to pay for housing or food, and that is enough. The drinks are cheap it is about 1 euro for a beer which is a little or a dollar per beer, and vodka is about the same, the clubs are amazing over there, I went to Zagreb and Dubornik in Croatia and Trebjine and Sarajevo in Bosnia, everything is Beautiful. The girls all look like models and throw themselves at American men so i can guarantee you will have a good time. I was there for a little over 2 months and i only spent about 1,000 but i am a women and then men bought me most of my drinks but i can guarantee that 4,000 is more then enough. Have a great trip i hope this helps

That equates to €31 a day.......its completely do able, but you will be a little broke from time to time, if you planning on doing something every day, visiting attractions or anything you prob wont be able to manage, but if you are staying with family and every few days you go somewhere then yes you should be ok, as long as you dont blow loads of money your first week there. Just thing €31 a day and if you dont spend that it carries on to the next day and the next day but try not to blow too much money.

Since you have places to stay and a car, $ 4,000.00 is certainly enough for 3 months incl. some entertainment. Have fun

ya that's plenty of money enjoy :)