I have an issue here. I'm going to be picking up my car tomorrow. Ok, so what's the issue right? Well, I'm going to be picking it up about 600 miles away. Here's my concern, obviously I'm going to have to drive that on the highway. The manual says that you aren't suppose to keep a constant speed or go over a certain mph until you reach a certain mileage. Obviously this is going to be really hard to follow. What damage am I going to end up causing by having to do this, or what could happen in the long term?

Also, looking to go to the 18" wheels. What issues is that going to cause if anyone knows? Is it going to throw of the speedometer or cause some other issues since the gearing is different?