Dominica is full of narrow, steep, sometimes not well marked roads.  The roads have no curbs, dangerous drainage ditches and drop offs.  They drive on the left.  Some major roads are under construction and repair. Four wheel drive is neccessary for many access roads.  The lowest stress way to get around is to hire a guide or taxi or bus.  In small towns you can ask around to find a driver.  The going rate is around $20/hr.  Gas is expensive so that rate is not pure profit.  Have a list of places you want to see and an open attitude, encourage your driver to show you their special places.