Cody did the whinning and barking when we go to a place that's very stimulating, like dogs shows as he's excited. He's completely fine though when we're actually in, lol. Sometimes when he's over excited he created a habbit of nibbling on anything he's allergic to, or at least it's always been something he's allergic too when I look at the tags. Not sure why but ever since he was young, he does this. Never puts holes in things but just does little nibbles, it's funny to see and a good back massager! He's doing it less and less now though.
Akbar also does the whinning when he's over excited. I have to give him quick pops and that has seem to help stop it for the most part. Of course I praise him when he stops.
About your dog getting excited in meeting other dogs, maybe you should not have him meet other dogs for a while or at least until he's stopped this. One thing that might have caused this is you probably let him go see other dogs because he was pulling and making a fuss to see the other dog. If your dog does this, turn the other way and leave. I wouldn't let this behavior to continue, for one it's annoying and I'm sure most owners are not happy to see a GSD running up to their dog and two I'm sure it's embarrasing for you.
Another thing I would try, when your dog starts carrying on while he's still
in the crate when you open the car door, shut the door and wait. If he is quiet, open it up again and if he starts again, close it. This might take a while but your patience will be rewarded in the end! Once you've gotten to the point where he can remain quiet, open the crate door and do not let him out until you say so. I am in the process of reteaching Akbar this since he's going through the butt head stage. If you can let your dog out and he's not whinning, clip his leash on and let him out. If at any time he starts, put him back in, shut the crate door, and the car door. Restart. During this, don't be angry, frustrated, talkative, nothing. Anything like big movements, high pitched noises, your energy can set him off and make him over excited again. Now, once your able to let him out and he's out of the car and he's still not whinning/barking, take a step or two while feeding him. If he's calm, continue, if not you know what to do. Do this until you're able to walk calmly inside. This might take a while, you might not even be able to get near the store your first week but your patience, energy, and dedication will all be rewarded.
Hope this helps.