Here’s a great article about the history of Streetview, with photos of the early equipment used.  They pursued it because it was “interesting.”

"It was a Frankenstein-looking car, but it let us capture enough data in the Bay Area. We had a van that we borrowed from the security team. It would go into the city, do some driving, and things would stop working and the computer gave us errors." - Luc Vincent, Engineering Director at Google Maps

“It was a Frankenstein-looking car, but it let us capture enough data in the Bay Area. We had a van that we borrowed from the security team. It would go into the city, do some driving, and things would stop working and the computer gave us errors.” – Luc Vincent, Engineering Director at Google Maps