Shared driveway a show-stopper?

[Daniel Walker]

I'm doing some analysis on a local 3/2 house.  The preliminary numbers make sense as a buy and hold; however, this property shares a driveway with the neighbor, yet no agreement is in place.  How much of a liability is this?  Should the lack of legal agreement simply be factored into the offering price, or should it be a show stopper?  Should i simply try to get an agreement with the neighbor in place before purchasing it?  Thoughts are much appreciated.