looking at a 99-06

[Low87]

I'm about to the point of selling my K5 and getting back to a pickup DD. A few reasons that are pointless to this thread.

I used to have a 98 ext cab. I sold it for the K5 because I could only get one car seat in the ext cab (in the middle, no room for little legs behind the driver or pass seat).

I've been looking at the crew cabs online, but can't tell how much extra room is back there. Anyone have experience fitting a carseat behind the front seats?

I know NOTHING about this style. I do notice differences between some years, and between Chevy & GMC. I prefer GMC just because, but wouldn't pass up on a good deal Chevy.

Any quirks on these to look for? I remember my friends had an '06 Tahoe that had some instrument problem. Could only be fixed by a dealership since the speedo had to be touched, and cost like $600. Anything similar in the pickups?

Any help is appreciated.