You can get some pretty great interest rates on auto loans at certain times, due to promotions or unusually low fed rates. I could have bought my car with cash but happily took a loan with a sub 2.5% interest rate.

Aside from low rates though I agree that there's not much point in getting a loan if you're able to comfortabely buy the car with cash, although many/most car buyers don't have that kind of financial flexibility.