as compared to my home radios/stereos?

All--

Have wondered for years why this is so--almost w/o exception,
on both AM/FM. On the car NGs, it was suggested that my house was blocking
signals, and that the metallic car acted as a big antenna. Neither seems
plausible, as my car next to the shop radio (which is terrible) still gets
good reception, and that if the metal in a car were so good, you wouldn't
need a car antenna.
I'm thinking it's the actual electronics. Any
opinions/explanations?
----------------------------
Mr. P.V.'d
formerly Droll Troll