General
Portugal has been pretty chilled on the whole, though it's not been quite as relaxing an experience as Spain; specifically in terms of finding overnighting spots. It hasn't been that difficult compared to some other countries we've visited, but it has presented a few challenges: chief amongst which is that almost every bit of rural ground everywhere is hunting territory and the only control applied is which selected subset of humans may lawfully slaughter wildlife for kicks there.
Also, though there are plenty of tracks around, they almost always appear to be in private rather than state ownership. It's apparent that most are very much in regular use, mainly affording access to intensively managed land of some or other description. In other words, pressure on land is palpably greater than in Spain and there just isn't the same perception of 'spare' bits of state-owned land on which to plonk a truck for the night and watch wildlife without either irritating someone or being mortally wounded.
A caveat is probably necessary. We've only 'done' what is probably - in terms of distribution of population - the least populated eastern tract of the country; so - should your preference for things natural and cultural be otherwise - your experience may be entirely different.
Lindgren Funnel Traps
We had no clue what these were until Mr Google was called upon. We'd seen stacks of funnels hanging from trees and other random structures and bickered no end as to their potential purpose. As it turns out, we were both actually satisfyingly close to eventually guessing. Basically, they're insect traps that are used for monitoring populations of various species in order to make the anthropogenic decision to then either conserve or destroy them. The traps apparently usually work by being impregnated with pheromones. Emma was oddly attracted to them.
Bakkies, Utes, Whatever
On this one, I can definitely get behind the Portuguese. Pickups of varying vintage from pre-2000 to brand new are extremely common and, to a man, all have had their questionably useful standard-issue load tubs replaced with a far more utilitarian cargo bed. Only in the Antipodes and South Africa am I aware of such a similar common sense approach to making a pickup, well... a pickup.