When to use imperfect of querer

Question

In Latin America we only use the imperfect of querer if we didn't get what we wanted, or if we got what we didn't want. Otherwise we use the preterite. Is it the same with the version of Spanish you teach?

Answer

Hola Marcos,
It is not exclusively for those cases but it is a common scenario for the use of "quería/no quería". For example:
Ella quería venir al cine pero no pudo. (She wanted to come to the cinema but she couldn't/didn't manage/didn't make it.)
Yo no quería estudiar medicina pero mis padres me obligaron. (I didn't want to study medicine by my parents made me.)
However this is not always the case. There isn't always that implication. If I take this sentence from the lesson for example:

Mis amigos querían averiguar la verdad. 
My friends wanted to know the truth.

This doesn't mean that they didn't succeed in knowing the truth in the end. It is simply stating what was happening at some point in the past. They could have found out or not, we don't know. 
Un saludo cordial
Inma