I think its a good investment. Having been (and still am) in the computer tech racket for a while I know the key to generating customers is exposure. Someone will see your vehicle parked and think about computers, which generates a lot of customers with problems that they otherwise would just "live with" for a while because they just don't want to deal with looking for a tech. (I've had people tell me this lol) Seeing a number while out and about gets them in the mode of thinking about what services they want.
Congrats on your new job!