There aren't that many car audio amplifiers (the TDA1562 and the TDA8511 run both off 12 V, so assuming the same for the broken one is reasonable, also assuming it's a TDA, too) in Multiwatt-11. Also you can assume it's a mono amplifier (since the TDA1562 probably drives the sub and the 8511 the four satellites only the center is left)
- TDA2004/5 (mono bridge)
- TDA7396 (mono bridge)
- TDA7350 (stereo / mono bridge)
- TDA7269/7263 (stereo, actually dual supply, but it could be used as a bridged single supply amp)
Most likely candidate is imho the 2004/5.