By the way it's a 10 inch sub and box to fit it that slides under the seats. My car is a 68 Cadillc Deville convertible.
Anyway - the installer I got a quote from is a higher end custom type shop. They specialize in show cars and classic.
How much for labor to install a head unit (with bracket in glove box), two speakers in doors with custom kick panel enclosures, a sub, an amp, a custom sub box?