General Motors option code
UM4
UM4: a General Motors factory option code reused for more than one part across 1979–1983 and 1 model — see the table for what it named each year, with installs and price where a source states them.
General Motors reused this code for more than one part over the years — read the "as named that year" column for what it meant on each row rather than assuming one meaning throughout.
1 model · 5 model years · 5 sources
Every sourced appearance
| Year | Model | As named that year | Price | Installs |
|---|---|---|---|---|
| 1979 | Buick Riviera | 8 Track & Signal Seeking AM/FM Stereo Radio w/Digital Readout order code (Buick option code) | $292 | Unknown |
| 1980 | Buick Riviera | 8 Track Tape & Signal Seeking AM/FM Stereo Radio With Digital Readout order code (Buick option code) | $298 | Unknown |
| 1981 | Buick Riviera | 8 Track & ETR AM/FM Stereo Radio order code (Buick option code) | $273 | Unknown |
| 1982 | Buick Riviera | 8 Track Tape & ER AM/FM Stereo Radio order code (Buick option code) | $193 | Unknown |
| 1983 | Buick Riviera | 8 Track Tape & ER AM/FM Stereo Radio order code (Buick option code) | $278 | Unknown |
Every row traces to the source it links from on that model's own year page; this table only collects them in one place.