Of all the places I've been, I think New Delhi ranks highest in terms of crazy driving conditions, which says a lot since I've also experienced the wonderful automotive artistry of Cairo and Beijing. I was fortunate enough to be in a car with a hired driver, and even then I was thinking it was nuts. You guys are probably borderline crazy yourselves for doing that on two wheels!
For those of you not familiar with just how densely populated New Delhi is, go to Google Maps and look at the satellite view to get a better idea of the scale. Searching on "New Delhi, India" will put you pretty much where the A marker is on the first map. The circle to the left of the marker is Connaught Place, and it is a massive complex of shops. Zoom into it, and you'll soon see just what kind of urban jungle these guys were in.
I commend all four of you for taking on this challenge!