is it all right to mount the cross-overs from the front speakers in the trunk and just run speaker wires from both the woofer and tweeters to the crossover?

I am wondering if the sound quality could somehow suffer from the crossover being further away from the speakers.

 

Distance from the amp to the crossovers will have no effect on sound. I wouldn't recommend putting them in the doors because they'll get wet. In one car i mounted them on the inside of the door with little holes for speaker wire. very neat. In another car i had the crossovers under the seats.
Currently i have the crossovers in the trunk.
I've seen a guy put them in the doors but inside plastic bags. don't know how long that lasted.

 

I too have seen crossovers in plastic bags, all I can say is lazy a$$ installers trying to make a quick buck instead of doing the job properly. The bag is not sealed and will still let moisture in. Do not put crossovers in the door unless it is on the interior side of the moisture barrier in the door.

 

^ I totally agree. Should you decide to put them in the doors - put them on the outside of the vapour barrier, between the barrier and the interior door panel.

Theoretically the crossover should be as close to the drivers as possible but it usually does not make much difference.

 

I personally prefer to run less wire rather than more. My front stage amp is in my trunk, so I could have mounted my crossovers there. But if I would have mounted the crossovers there, I would have had to run 2 pairs of speaker wires rather than 2. I'm a cheap dutchman, and didn't want to waste that wire, so my crossovers are up front.

My favourite location for crossovers is on the floor of the centre console - (Behind where the deck is mounted) Feet don't come near them, and they are raised from the rest of the floor so winter slush doesn't hit them either. Even on compact Japanese cars there is room to mount them there. (My Cars are a Toyota Tercel and a Subaru Legacy).