If you got the VIN# and ran it on the free Russian site you could confirm if it was delivered new to Mexico. (I have never heard of any 500s that were)

Very likely it would have had a low compression engine so as to take into consideration the crap gas that was sold there.

Unleaded ("sin plomo") gas was very hard to find in Mexico back in 1984.

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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

1967 Mercury Cougar, 49k

2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)