Autonet Mobile just notched another one in its belt by scoring a deal to hook GM's Cadillac CTS up with integrated WiFi. Starting this April, folks who splurge on one of these sports sedans will be treated to WiFi (a $499 dealer-installed option) in the car, and best of all, it uses a new, smaller router than can be easily transferred to another vehicle that's equipped with an identical dock. The agreement is a first for Caddy and also the first luxury brand that Autonet Mobile has managed to invade. 'Tis a shame that monthly subscription still starts at $29 -- we get the feeling that even the affluent won't much ca