I think you should add posters on the windows and/or walls, the ones that advertise new burgers and stuff

I like it.

The only comment I have is that the windows are the same level as the main doors and look like doors too.

If this is like your McD's then fair enough and I'll keep quiet   ;o)

(...and all Mc Donalds have 3 drive thru windows including a mysterious second one that never seems to be used...lol...only jokin')

THis is nice :D i like it.. but i would suggest adding the menu for drive-thru

Also your drive-thru has no menu.

It reminds me of that Counter Strike Source level! Awesome!

Not bad... but it's a little too flat : \