2/10 for stealing Sering's then. ~4/10 if it would've been original. Quite hard to decide.
The design is very bland, and I am not really into that "roof" at all.
Additionally, if another car parked next to that one, it would be impossible for it to get out without going over the bump, and by the looks of it the bump is a bit higher than the bumper. Unless you wanted to say "forget you" to the drivers, that's a really bad planning.
The stripped interior is weak. And except drinking I don't see anything related to "Diner".
Also you could've used some actual windows.
Also all tables are for 2, yet diners usually have tables for groups too. And that's 4 and up.