Plannig a trip to Peru,Bolivia ect Buying a bike or car whic
 

Im just starting to plan a trip to South America, im unsure about another trip on a bike or to buy a cheep car and see how far i get.
Can anyone tell me anything like road conditions around Peru, Bolivia, Brazil, Chile etc pros and cons about riding a bike compared to a car.
And how difficult it is to buy a vehicle with very little spanish.
Any info would be Great
Thanks
Craig