diff --git a/selfdrive/car/fw_versions.py b/selfdrive/car/fw_versions.py
index 1c0d5003ec..3c18c2e7bd 100755
--- a/selfdrive/car/fw_versions.py
+++ b/selfdrive/car/fw_versions.py
@@ -1,7 +1,8 @@
 #!/usr/bin/env python3
 from collections import defaultdict
-from typing import Any, Dict, List, Set
+from typing import Any, DefaultDict, Dict, List, Optional, Set, Tuple
 from tqdm import tqdm
+import capnp
 
 import panda.python.uds as uds
 from cereal import car
@@ -27,7 +28,8 @@ def chunks(l, n=128):
     yield l[i:i + n]
 
 
-def build_fw_dict(fw_versions, filter_brand=None):
+def build_fw_dict(fw_versions: List[capnp.lib.capnp._DynamicStructBuilder],
+                  filter_brand: Optional[str] = None) -> Dict[Tuple[int, Optional[int]], Set[bytes]]:
   fw_versions_dict = defaultdict(set)
   for fw in fw_versions:
     if (filter_brand is None or fw.brand == filter_brand) and not fw.logging:
@@ -36,14 +38,14 @@ def build_fw_dict(fw_versions, filter_brand=None):
   return dict(fw_versions_dict)
 
 
-def get_brand_addrs():
-  brand_addrs = defaultdict(set)
+def get_brand_addrs() -> Dict[str, Set[Tuple[int, Optional[int]]]]:
+  brand_addrs: DefaultDict[str, Set[Tuple[int, Optional[int]]]] = defaultdict(set)
   for brand, cars in VERSIONS.items():
     # Add ecus in database + extra ecus to match against
     brand_addrs[brand] |= {(addr, sub_addr) for _, addr, sub_addr in FW_QUERY_CONFIGS[brand].extra_ecus}
     for fw in cars.values():
       brand_addrs[brand] |= {(addr, sub_addr) for _, addr, sub_addr in fw.keys()}
-  return brand_addrs
+  return dict(brand_addrs)
 
 
 def match_fw_to_car_fuzzy(fw_versions_dict, log=True, exclude=None):
@@ -214,7 +216,8 @@ def set_obd_multiplexing(params: Params, obd_multiplexing: bool):
     cloudlog.warning("OBD multiplexing set successfully")
 
 
-def get_fw_versions_ordered(logcan, sendcan, ecu_rx_addrs, timeout=0.1, num_pandas=1, debug=False, progress=False):
+def get_fw_versions_ordered(logcan, sendcan, ecu_rx_addrs, timeout=0.1, num_pandas=1, debug=False, progress=False) -> \
+  List[capnp.lib.capnp._DynamicStructBuilder]:
   """Queries for FW versions ordering brands by likelihood, breaks when exact match is found"""
 
   all_car_fw = []
@@ -235,7 +238,8 @@ def get_fw_versions_ordered(logcan, sendcan, ecu_rx_addrs, timeout=0.1, num_pand
   return all_car_fw
 
 
-def get_fw_versions(logcan, sendcan, query_brand=None, extra=None, timeout=0.1, num_pandas=1, debug=False, progress=False):
+def get_fw_versions(logcan, sendcan, query_brand=None, extra=None, timeout=0.1, num_pandas=1, debug=False, progress=False) -> \
+  List[capnp.lib.capnp._DynamicStructBuilder]:
   versions = VERSIONS.copy()
   params = Params()
 
@@ -286,11 +290,11 @@ def get_fw_versions(logcan, sendcan, query_brand=None, extra=None, timeout=0.1,
           set_obd_multiplexing(params, r.obd_multiplexing)
 
         try:
-          addrs = [(a, s) for (b, a, s) in addr_chunk if b in (brand, 'any') and
-                   (len(r.whitelist_ecus) == 0 or ecu_types[(b, a, s)] in r.whitelist_ecus)]
+          query_addrs = [(a, s) for (b, a, s) in addr_chunk if b in (brand, 'any') and
+                         (len(r.whitelist_ecus) == 0 or ecu_types[(b, a, s)] in r.whitelist_ecus)]
 
-          if addrs:
-            query = IsoTpParallelQuery(sendcan, logcan, r.bus, addrs, r.request, r.response, r.rx_offset, debug=debug)
+          if query_addrs:
+            query = IsoTpParallelQuery(sendcan, logcan, r.bus, query_addrs, r.request, r.response, r.rx_offset, debug=debug)
             for (tx_addr, sub_addr), version in query.get_data(timeout).items():
               f = car.CarParams.CarFw.new_message()