diff --git a/opendbc_repo/opendbc/car/car_helpers.py b/opendbc_repo/opendbc/car/car_helpers.py
index 0e4a5fc2fd..e6d1e18b0c 100644
--- a/opendbc_repo/opendbc/car/car_helpers.py
+++ b/opendbc_repo/opendbc/car/car_helpers.py
@@ -278,6 +278,10 @@ def get_car(can_recv: CanRecvCallable, can_send: CanSendCallable, set_obd_multip
     carlog.error({"event": "car doesn't match any fingerprints", "fingerprints": repr(fingerprints)})
     candidate = "MOCK"
 
+  if source != CarParams.FingerprintSource.fixed and candidate == 'TOYOTA_PRIUS':
+    from opendbc.car.toyota.values import automatic_prius_candidate
+    candidate = automatic_prius_candidate(candidate, car_fw)
+
   CarInterface = interfaces[candidate]
   params_options = {'auto_pedal': False} if source == CarParams.FingerprintSource.fixed and candidate in interface_names['gm'] else {}
   CP: CarParams = CarInterface.get_params(candidate, fingerprints, car_fw, alpha_long_allowed, is_release, docs=False, **params_options)
diff --git a/opendbc_repo/opendbc/car/toyota/tests/test_retrofit_discovery.py b/opendbc_repo/opendbc/car/toyota/tests/test_retrofit_discovery.py
new file mode 100644
index 0000000000..7852a4043b
--- /dev/null
+++ b/opendbc_repo/opendbc/car/toyota/tests/test_retrofit_discovery.py
@@ -0,0 +1,83 @@
+from unittest.mock import patch
+
+import pytest
+
+from opendbc.car import car_helpers, structs
+from opendbc.car.toyota.values import CAR
+
+
+def rack(**changes):
+  values = {'ecu': structs.CarParams.Ecu.eps, 'fwVersion': b'8965B47070' + bytes(6),
+                'address': 0x7A1, 'bus': 0, 'brand': 'toyota', 'subAddress': 0, 'logging': False}
+  values.update(changes)
+  return structs.CarParams.CarFw.new_message(**values)
+
+
+def identify(fw, *, release=False, forced=None, adapter=None, source=None):
+  # Native DSU commands are present on bus0 and mirrored on the camera bus.
+  fp = {0: {0x343: 8, 0x4CB: 8, 0x1D2: 8, 0x1D3: 8, 0x262: 8}, 1: {},
+        2: {0x343: 8, 0x4CB: 8}}
+  if adapter is not None:
+    fp[0][0x2FF] = adapter
+  detected = (CAR.TOYOTA_PRIUS, fp, '00000000000000000', fw,
+              structs.CarParams.FingerprintSource.fw if source is None else source, True)
+  with patch.object(car_helpers, 'fingerprint', return_value=detected):
+    return car_helpers.get_car(lambda wait_for_one=False: [], lambda _: None, lambda _: None,
+                               False, release, forced_candidate=forced).CP
+
+
+@pytest.mark.parametrize('release', [False, True])
+@pytest.mark.parametrize('source', [structs.CarParams.FingerprintSource.fw, structs.CarParams.FingerprintSource.can])
+def test_automatic_stock_retrofit_matches_explicit_profile(release, source):
+  automatic = identify([rack()], release=release, source=source)
+  explicit = identify([rack()], release=release, forced=CAR.TOYOTA_PRIUS_RETROFIT)
+  assert automatic.carFingerprint == CAR.TOYOTA_PRIUS_RETROFIT, 'PRIUS_RETROFIT_AUTO_IDENTITY'
+  assert not automatic.dashcamOnly
+  assert automatic.safetyConfigs[0].safetyParam == 585
+  assert not automatic.openpilotLongitudinalControl
+  assert automatic.pcmCruise
+  assert not automatic.alphaLongitudinalAvailable
+  assert automatic.fingerprintSource == source
+  a, b = automatic.to_dict(), explicit.to_dict()
+  a.pop('fingerprintSource')
+  b.pop('fingerprintSource')
+  assert a == b
+
+
+@pytest.mark.parametrize('release', [False, True])
+@pytest.mark.parametrize('length', [4, 8, 7])
+def test_automatic_retrofit_retains_existing_adapter_admission(release, length):
+  automatic = identify([rack()], release=release, adapter=length)
+  explicit = identify([rack()], release=release, adapter=length, forced=CAR.TOYOTA_PRIUS_RETROFIT)
+  assert automatic.carFingerprint == CAR.TOYOTA_PRIUS_RETROFIT, 'PRIUS_RETROFIT_AUTO_IDENTITY'
+  a, b = automatic.to_dict(), explicit.to_dict()
+  a.pop('fingerprintSource')
+  b.pop('fingerprintSource')
+  assert a == b
+  assert automatic.dashcamOnly == (length == 7)
+
+
+@pytest.mark.parametrize('changes', [{'fwVersion': b'8965B47060' + bytes(6)}, {'bus': 1}, {'brand': 'honda'},
+                                      {'address': 0x7A0}, {'subAddress': 1}, {'logging': True},
+                                      {'fwVersion': b'8965B47070'}])
+def test_unproven_rack_does_not_change_identity(changes):
+  cp = identify([rack(**changes)])
+  assert cp.carFingerprint == CAR.TOYOTA_PRIUS
+
+
+def test_missing_or_conflicting_eps_does_not_change_identity():
+  for fw in ([], [rack(), rack(fwVersion=b'8965B47060' + bytes(6))]):
+    assert identify(fw).carFingerprint == CAR.TOYOTA_PRIUS
+
+
+def test_manual_original_choice_is_preserved_and_stays_blocked():
+  cp = identify([rack()], forced=CAR.TOYOTA_PRIUS)
+  assert cp.carFingerprint == CAR.TOYOTA_PRIUS
+  assert cp.dashcamOnly
+  assert cp.fingerprintSource == structs.CarParams.FingerprintSource.fixed
+
+
+def test_developer_fixed_fingerprint_is_preserved():
+  cp = identify([rack()], source=structs.CarParams.FingerprintSource.fixed)
+  assert cp.carFingerprint == CAR.TOYOTA_PRIUS
+  assert cp.dashcamOnly
diff --git a/opendbc_repo/opendbc/car/toyota/values.py b/opendbc_repo/opendbc/car/toyota/values.py
index e0ea229275..deeef02119 100644
--- a/opendbc_repo/opendbc/car/toyota/values.py
+++ b/opendbc_repo/opendbc/car/toyota/values.py
@@ -476,6 +476,16 @@ def get_platform_codes(fw_versions: list[bytes]) -> dict[bytes, set[bytes]]:
   return dict(codes)
 
 
+def automatic_prius_candidate(candidate, car_fw):
+  if candidate != CAR.TOYOTA_PRIUS:
+    return candidate
+  eps = [fw for fw in car_fw if fw.ecu == Ecu.eps]
+  if eps and all(not fw.logging and fw.bus == 0 and fw.brand == 'toyota' and fw.address == 0x7A1 and
+                 not fw.subAddress and bytes(fw.fwVersion) == b'8965B47070' + bytes(6) for fw in eps):
+    return CAR.TOYOTA_PRIUS_RETROFIT
+  return candidate
+
+
 def match_fw_to_car_fuzzy(live_fw_versions, vin, offline_fw_versions) -> set[str]:
   candidates = set()
 
diff --git a/prebuilt.json b/prebuilt.json
index 40ffb34a39..a74819ff5a 100644
--- a/prebuilt.json
+++ b/prebuilt.json
@@ -1 +1 @@
-{"protected_inventory_sha256": "72fdf29ec9a457fecef91db32719ed60947bdc93c11598a4e3b0f32b0e5bc188", "schema_version": 1}
+{"protected_inventory_sha256": "68d6880928852d9065453f4015fdfb139ea8759d2ce8d12c4d23cf9cd6285244", "schema_version": 1}
diff --git a/tools/ci/run_vehicle_tests.py b/tools/ci/run_vehicle_tests.py
index 9047dd9873..13f782f133 100644
--- a/tools/ci/run_vehicle_tests.py
+++ b/tools/ci/run_vehicle_tests.py
@@ -154,6 +154,7 @@ AOL_LIFECYCLE_TARGETS = (
   "openpilot/starpilot/car/toyota/tests/test_camera_2aa_native.py",
   "openpilot/starpilot/car/toyota/tests/test_prius_sdsu_filter.py",
   "openpilot/starpilot/car/toyota/tests/test_prius_sdsu_callers.py",
+  "opendbc_repo/opendbc/car/toyota/tests/test_retrofit_discovery.py",
   "openpilot/starpilot/galaxy/tests/test_prius_sng_settings.py",
   "openpilot/starpilot/car/toyota/tests/test_sng_resume.py",
   "openpilot/starpilot/car/toyota/tests/test_sng.py",