When you run your own consultancy business, your base will often be in your home. But your clients are all over the place, and sometimes you have to go and talk to them.
For instance, if you're aquiring, and an unknown client pops up, you often need to go over there an sweettalk them into the deal of their lifetime. So traffice is unavoidable. And you want to make a good impression, by showing up mostly 10 minutes before the actual appointment. But traffic is unpredictable and can slow you down. So what do you need ? Yes, navigation.
Some will think they don't, and say navigation is all about gadgets, but I can tell you, it's not. A proper navigation device will do these tricks for you :

• Calculate the fastest route to your destination
• Re-calculate if roads are closed or one way only
• Check traffic while you're driving for jams, accidents and road work (TMC adapter needed) Guide you through traffice with clear indications so your mind can be with the appointment you're going to.

I can tell you from experience that a good navigation device will get you there relaxed and calm, instead of frustrated from heavy traffic and timeloss. A litle hat-tip is this : Most navigation devices allow you to calculate the route when you're still home. That will tell you how long the trip will take so at what time you'll need to leave.