I would suggest skipping that 'grey import' and look for the 'official
import' (meaning the car was built by the manufacturer specifically to
meet the US regulations).

During the heady time of 'grey import' in the early 1980s, there were so
many discrepancies and variations in the quality and type of conversion
work (some were done with OEM components whilst others 'home-made'
fabrications). Fraud was rampant during that time (recycling the photos
of conversion work done when submitting to NHTSA). Some vehicles caught
fire due to poorly engineered and fabricated components. Some failed to
perform in the collision as required, i.e. omitted bars in the doors to
prevent the intrusion.

If you rather prefer this, you can import any Mercedes-Benz that is at
least 25-year-old to the USA without any conversion work to meet US
safety regulations. However, you will have to modify the emission
control to meet EPA level of the year manufactured.

By the way, Mercedes-Benz USA lobbied successfully to end the 'grey
importation' in 1988 as it made a very poor and regrettable decision to
omit 500SEL, 500SEC, and 500SL from the US model range. 380SEL, 380SEC,
and 380SL were terribly overpriced and grossly underpowered. The grey
importation fulfilled the American appetite for more powerful V8 motors...

Another reason to f.ck Mercedes-Benz USA. Still no smart cars, still no
B-Class, and still no more C-Class Sportcoupé for US market in spite of
escalating fuel price. Zap, Inc., the official importer of smart cars
for US market, reported lot of harassment from Mercedes-Benz USA to stop
the alternative market.