As of now, I don't have any plans for that weekend, but it is a long weekend here and I am thinking of going somewhere. If I am here, I'd love to meet up. I will definitely let you know.
All the street signs here are in Czech. There may be some German at the border, but not generally. This shouldn't be too much of a problem, though. I've rented a car several times and drove to Germany without a clear plan and didn't have too may problems. There are not a lot of highways here, and if you are on the one to Prague, you won't really need to change... Just follow the signs for Praha.
I don'r know if your plans have made it to solid form yet, but just in case. We will be in Prague next Wed. I am thinking that we are probably going to get in somewhere aroun 10:00 a.m. If you are going to be available let me know and if not I hope you have a wonderful time on your own vacation.
I will be here when you are here. I won't be leaving until Thursday morning. But I have a solid day of work on Wednesday, but I will be free in the early evening if you want to meet up. Maybe we can walk around a little and see Prague at night (it's beautiful!) and maybe grab a good Czech dinner. Basically, I'd be up for anything you're interested in for the short time you will be here. I'll send you an email with my contact information.