An early example of Iberian-Anglo cross-cultural exchange is Simon Ockley's 1709 translation of Ibn Tufayl's Hayy Ibn Yaqzaan: www.erbzine.com/mag18/yaqzan.htm
I do not quite agree with the methodological dialectics of European materialism and Iberian idealism. Far fetching, seems...
Stoic Seneca's case shows that Hispania was an important part of Latin-Romanized Europe. In fact, Spain in the time of the Stoics was spearheading regional philosophy.
What is called by Spanish philosophers "Senequismo" is in fact a consequence of the great influence of Lucio Seneca. Rafael Gambra argues that current Spanish fatalism, indifferentism, deeply humane and compassionate culture all at once are legacies of Senequismo. (You are asking for distinctive 'traces'...Gambra gives you one)
Then, we have next great philosopher Averroes from Cordoba in the 12th C. (South Spain, then Islam) who would link Aristotle to the Middle Ages. Equally from Cordova but of Jewish origin, we have Maimonides (great importance in the interpretation of Aristotle).
You might say, that the latter two are not really "Spanish" by culture. Well prior to Reconquista, there was only Roman Hispania (Sueves and Vandals were takers), and it happens that the Iberian peninsula was conquered by Arabs.
After a long span of centuries...we might count the 17th Century Espinosa (better known by his Germanic spelling Spinoza). He was indeed a Spaniard who took [political] refugee in Holland. You recall his "Omnis determinatio est negatio"?
For me, it is not clear whether Spinoza was a Spanish or, in your category, European philosopher. The difference is blurry to me. This was the epoque of continental rationalism. "Idealism" that you mentioned is more strictly opened by Kant. Of course, Kant was a Prussian.
We do not know much about but there is a link between German (main European philosophy) and Spain: Sanz de Rio (con acento a la i).
Then...perhaps Jaime Balmes (19th C.), Catalonian, 'con perdon,' and the great Spanish thinker Unamuno.
After this abridged detour, could we say that there is a clear ditinction between European materialism and Iberian idealism? I leave the answer to you, Carlos. Un abrazote.
In fact, the largest and clearest distinguishing feature is based on the ethical antagonism between individualism versus cooperation, or, if you prefer, rational calculism versus emotional experience of the vital value.