On October 23, 2006, the Italian government made Andretti a Commendatore of the Order of Merit of the Italian Republic (OMRI), the most senior Italian order of merit, in honor of Andretti's racing career and commitment to his Italian heritage

What the link doesn't mention is that only one other motorsports personality holds that honor, one Enzo Ferrari. That alone should tell you how highly Mario Andretti is thought of in his country of birth.

I became a fan while watching him race NASCAR... which was not called that at the time. LOL.

wiki - At the height of his IndyCar career, Andretti also made thirty appearances in top-level stock car racing from 1965 to 1969.

wiki - NASCAR was founded by William France, Sr. on February 21, 1948 with the help of several other drivers of the time. (as the National Association for Stock Car Auto Racing)

NASCAR was clearly established by the 1960s. USAC also sanctioned races but was never a dominant player in stock cars. Anyway, the Daytona 500 has always been NASCAR's premier event, which was the achievement cited in the wiki entry.

Not all stock car racing was under their auspices, however.

But, he was my favorite stock car racer until he moved to Indy cars. Then, he was my favorite Indy car racer.