[3] The same season, Lewis joined the Lamborghini GT3 Junior Program, representing the team in IMSA competition alongside Richard Antinucci, Edoardo Piscopo, and Cedric Sbirrazzuoli.

For 2018, alongside a return to the Lamborghini Super Trofeo North America, Lewis signed with P1 Motorsports to compete in the IMSA Prototype Challenge, sharing the #17 entry with Matt Dicken.

[10] Later that season, he made his return to the Michelin Pilot Challenge, the same series in which he'd begun his sports car racing career seven years prior, signing with Canadian team Motorsport in Action.

[12] In 2021, Lewis joined K-Pax Racing's two-car effort in the returning Pro class of the GT World Challenge America, partnering with Lamborghini factory driver Giovanni Venturini.

[14] After continuing to compete predominantly in Lamborghini machinery during 2021 and 2022, Lewis returned to Paul Miller Racing ahead of the 2023 IMSA SportsCar Championship season.