Like he said, but unless the Impala is dramatically different from the Fleetwood, (that I don't know, someone who's more familiar with the differences and similarities of the two models would have to weigh in) it's still a tight fit with some units. I put in a Pioneer AVH x5600bhs and to use my rear USB inputs and RCA inputs/outputs, I had to use 90° adapters. My unit is a 2013 model though, and when I've looked at pictures of some of their newer units it looks like they've recessed all the connectors further back into the unit which would alleviate that. I'm not really familiar with any other brands though, but most Pioneers have everything you're looking for, at least in the double DIN stuff. However I know that's another issue with the Impala's, double DINs usually require more work to make fit. But I've got HD radio, Sirius ready, bluetooth and tons of RCA ins and outs. It seems to me though that most of their stuff regardless of whether it's double or single DIN has all those features standard these days. And other name brands are likely similar in features.