Chevy Impala vs. Pontiac grand Prix - need advice

[JJEH]

Hey Guys,

kinda need your opinions. We tried to get a '06 Grand Prix but somehow the Dealership did not what they were supposed to do. In fact, we didn't get the car.

Since a couple of weeks we are specifically looking for either an <span style="font-weight: bold">Impala</span> or <span style="font-weight: bold">Grand Prix</span>.

But what is your experience, or rather which one would you prefer?

<ul style="list-style-type: disc">[*]2000-2005 Impala 3.4 or 3.8 naturally aspirated?[*]2006 -present Impala 3.5, 3.6, 3.9? Or the[*]2004-2008 Grand Prix 3.8 naturally aspirated?[/list]
My biggest concern is reliability!

Thanks for any opinions!