Traffic on Rt 59 is irrelevant since you wouldn't use that to get to downtown Naperville. Probably the best option, whether you are coming from the east or the west, is the Winfield Road exit on I-88 and follow the signs to downtown. Parking *can* be hard to come by but I've never had to park more than a couple of blocks from my intended destination, and usually for free.

I'm not sure that you are more likely to get door dinged in Naperville than anywhere else.

Another easy way to get to downtown Naperville is to take Metra. The Naperville station is just a few blocks from the downtown restaurant district. However, service on weekends is infrequent.