Never trusted them.
I have an old jeep with no top or doors but it is a manual transmission so that could beat a few lesser seasoned thieves.
Besides it is geared so low, it tops at 45. The steering gearbox is worn out so that slow someone down a little also.
Heh.
My college ride was a '46 Willys CJ2A, flat head four, 5.38 rear end, two speed transfer case, the whole headache.
Was a little faster than 45, but my jeep club was usually annoyed when I went along on mountain rides as they liked to run together on the highway to and from... and they had to slow to my maxed out, screaming speed of barely around 55.
:) It was great!