Cadillac will join Chrysler and BMW as one of the few carmakers to offer in-car Internet access when it rolls out its service from April. The system is designed and built by a company called Autonet Mobile, and will deliver access speeds of up to 800Kbps with the lowest service plan available from $29.

Passengers will be able to hook up to the ‘net by using any Wi-Fi enabled device such as a notebook, PDA or smartphone. The $29 access fee will get you 1GB of bandwidth per month but if you opt for the $59 plan you’ll get 5GB.

Cadillac's Wi-Fi will be portable

Cadillac's Wi-Fi will be portable

Cadillac will showcase the Autonet Wi-Fi router at next month’s New York Auto Show inside a CTS sedan, but we expect them to roll out the system to more models in the near future. While both the Cadillac and Chrysler systems are built by Autonet and priced at $499 plus dealer installation charges, the one inside the Caddy is portable and you will be able to move it between cars.

Both 2.5G and 3G networks are supported by Cadillac Wi-Fi but you’ll take a significant speed hit when using the former. Still, the system could come in handy for travelling salespeople or sales teams that need constant contact with the office.

Although Autonet touts the ability to use the system for more consumer applications such as keeping the kids entertained on a long trip, the relatively low bandwidth option of 5GB means you’ll have to be careful when using streaming media. Still, the $59 price point is comparable to similar plans offered by AT&T and Verizon.