Thanks Brian, I like the number one too... Number #2, no la...too dangerous, especially when you have kids.

Number #3 is only for those with empty center console, mine cannot.

Guess need to find those big 10" mess type grill to really protect it, in case #1 become a reality.

amjb76 - JL, not bad, but JL tend to require big box to meet its full potential.Of course, there is always a workaround.
If you have enough juice, check out Audison or Realm. If I understand it correctly, it only require a small box.

... Sound wise, someone need to sacrifice and tell us lor.    

try to look for 8inch RS Audio or 9inch focal, both very good in small enclosures.  i have had frens install them in a peugeot 406 passenger footwell, nissan snetra footwell and latest is estima below dashboard on floor

How do u do it? Mind uploading some photos? And what brand and type? Cos I'm interested to have it somewhere there as well. One of the shops i went told me that it's doable under the glove compartment.  Not too sure how it's done.

If you dont require much bass, then I guess a 8" might suit you. the 8W1V2 sealed enclosure requires 0.38cuft only. IF space is a big issue here, try hook up a 6W3V3, in a 0.15cuft enclosure. can hide it easily. haha.

if you're going for 3way setup, then yes, you are probably correct. however for a 2 way setup where the mids and mid bass share the same output, you will have this dilemma: crossover freq too high you dont get enough bass, too low, you get your ICE clarity muddied.

and really, are you going to trust your ICE on some specs on paper, or you're going to trust your ears?
again, if all you're listening is soft/sentimental classics, yeah, 8" is probably enough. however anything more than that, i personally (welp! personal opinions) dont think 8" is enough. AT LEAST also get a 10" and perhaps even get it ported.