There's the Triple XXX Family Restaurant in West Lafayette, which is apparently still a drive in--I think I went there once on my many trips to Cincinnati and sat inside. It was quite a while ago so I don't remember a lot of specifics, but I didn't go back, so I must not have been thrilled with the food, but it is what you're looking for!
There are are several Skyline Chilis in the Indianapolis area, if you haven't tried Cincinnati chili but want to--not a drive in, but always quick service. This has become my go-to in trips to/from Cincinnati to get one last cheese coney, now that we have Culver's here.
There is also Shapiro's Deli in Indianapolis (again, not a drive-in, but quick service).
Triple XXX Family Restaurant
2 N. Salisbury
West Lafayette, IN
https://www.triplexxxfamilyrestaurant.com/Shapiro's Deli
808 S. Meridian
Indianapolis, IN
https://shapiros.com/