It's a pickup truck--a vehicle historically built for utility, not comfort—but the 2008 Mazda B-Series is better in this regard than many similar vehicles.
Car and Driver says there's "not much passenger space" in the Mazda 2008, although Cars.com reports a "roomy cab with a standard three-place front bench seat." As for Mazda B-Series' standard cab vs. extended, the latter offers slightly more headroom and storage room behind the seats, but beyond this, there's little difference between the two. ConsumerGuide notes that the 2008 Mazda's extended "cab model has slightly more seat travel and seatback recline angle than class rivals," but Kelley Blue Book advises that the small jump seats behind the front row are "best used for short trips only."
Cars.com reports that Mazda 2008 "occupants get a fold-down armrest, and storage pockets are installed on the seatbacks." ConsumerGuide also likes the "better-than-average behind-seat storage space" of the regular cab, and says the extended version "can carry lots of stuff." Overall, the 2008 Mazda B-Series is "designed for the active person who needs to haul stuff like jet skis, scuba gear and mountain bikes," according to Autoblog; there's plenty of room for all that gear in the generous 6-foot bed as reported by Cars.com.
According to Kelley Blue Book, the seats of the 2008 Mazda "have a richer pattern and the instrument panel features [more readable] white-faced gauges." While not a glowing endorsement, ConsumerGuide says that "interior materials are appropriate for the price, and all models we've tested have been solidly built." As for noise, this source reports "the interior is well isolated from engine, wind, and road noise," though the Mazda 2008 is not "as car-quiet as the Dodge Dakota."