Although one of the more obvious references, Ash's favored mode of transport, the Oldsmobile, returns in several guises. Firstly, we see him still driving it around town (it seems to run surprisingly well considering the literal battles its been through), but there's also a hidden Easter Egg in an unexpected place. When Ash consults the 'Books From Beyond' business card, we see the address is 1973 Olds Road, Berkley, Michigan. This is clearly a reference to the 1973 Oldsmobile Delta 88 he drives.
The Oldsmobile actually features in all Sam Raimi's movies -- including Oz: The Great and Powerful -- and the one seen in Ash vs The Evil Dead is the same one from the original movies. It is owned by Sam Raimi and was bought new for him back in the 1980s by this father.