Legal width for right of way for cars

My neighbour is claiming 16 foot right of way through the south boundary of my residential property. The reason being there are coconut trees and a dog house in a parellel line 2 feet along the southern boundary... In such case, I would lose a hue amount of land of high value as the path way is around 55feet long. They have been using the path way over 35 years but, not sure they owned cars for more than 20 years. If not, do I have to give them right of way wide enough to trespass their cars??? They had been changing their cars and at times they dint own any cars for some long intervals... Does these intervals count in the number of years they have been using the cars??? Is it necessary that the cars has to be owned by the person who is claiming the right of way??? Or could it be in his immediate relatives names. I.e sons or wifes??? If I file a case against them in violation of my property, is it their responsibility to prove that they have been owning and using the cars over 20 years over my property. Can they claim pathway dividing my property putting the trees and dog house near to the southern boundary wall, alongside i wish to give them pathway... For your information, the pathway to my property doesn't touch the public road. It only makes way to another pathway(private right of way- 16feet) legally given to both of us by the landowner toward the west of my property. And it is that pathway that connects 3 of us to the public road... But I have a gate of 16feet width towards the south west corner of my property opening to the said 16 feet pathway to the mentioned public road To add on, my neighbour, who is raising this claim owns the land behind his current property and also purchased the property just behind my property, which I had sold earlier to another person giving right of way(8foot) through the western boundary of my property, which also connects to this 16 foot pathway to the public road... But I'm not sure whether he has purchased these properties in his wife's name or son's... All I know is my property is surrounded by pathways!!!! And all these properties are lying with any demarcation, except the neighbour on the western side, who gave us the common pathway to the public road. Also note that there is no other way than this 16 foot common pathway to the public road... Will I lose out my valuable property again, if my neighbour claims right of way 16 feet over my property...?? Please advice