The great thing about the SWE1200 is that it comes with everything you need in the box but like you said you need a component type cable (rca cable) which you need to buy that goes between the back of your headunit and the subs amp. Something I encountered with this was there is not a lot of room when you are pushing your headunit back in and so the RCA lead cant be ones with a connector that take loads of room, you need to either but two of these:
http://www.amazon.co.uk/Degree-Phono-Socket-Single-Adapter/dp/B003OSS1QU/ref=sr_1_fkmr2_2?ie=UTF8&qid=1424284087&sr=8-2-fkmr2&keywords=rca cable 90 degree 30cm
or buy something like this
http://www.amazon.co.uk/Ex-Pro®-ProAV-Audio-Cable-Degree/dp/B007P2J7AA/ref=sr_1_fkmr2_3?ie=UTF8&qid=1424284087&sr=8-3-fkmr2&keywords=rca cable 90 degree 30cm (BUT shorter - 30cm if you are mounting amp behind the dash)
The way I have it all set up is the wired remote control in the cubby hole under the traction control buttons - need to drill an 8mm hole possible bigger to get the cable in there. The control box (amp) for the sub I have located behing the dash board - behind the clocks , you will find there is loads of room there and is a good place to mount it. I dont have a pic unfortunately. I used some really strong number plate double sided pad to hold the amp in place securely. the RCA cable doesnt need to be longer than 30 cm if you mount it here. You also need to fix the earth cable somewhere and you will find there is loads of great earth points under the dashboard - I undid a nut and stuck the earth spade under the nut and tightened it.
All in all its really really easy to fit it but will take a little while - perhaps 2 hours to do a tidy job. I had never removed the top of the dash but its a doddle and really easy. The hardest part of the install is getting the power cable to the battery, this took the longest and you probably know but there is a rubber bung behind the glove box - you will need to be on your back to get to it, I used the tube from a bic biro to stick through the bung but also used a philips head screw driver to expand the bung hole (did i say bung hole? lolz) and then feed the cable through the biro. It comes out behind the sound deadening material behind the expansion tank (which needs unmounting.) quite far down. Pain of a job that and is a back killer.
The sub sits under the passenger seat and the cable that goes from the amp to the sub routes from the dashboard, down behind the heater controls, under the ashtray and at this point you have a choice of running the cable under the carpet but this means unbolting your passenger seat and removing it (takes 15 mins and is easy just 4 x 13mm nuts that need removing under the car using a 13mm deep socket + 10cm extension bar (std 13mm socket will not reach , I had to buy the socket.)) or running the cable under the trim of the gearstick, then under the hand brake trim. If you run it under the hand brake you will see a little bit of cable but perfectly acceptable.
I would recommend taking the seat out as it will allow you to run the battery cable a LOT easier as you will be able to lie on your back on the car floor rather than the side sill, and the install will be a lot cleaner. You dont need to screw the sub down or mount it or anything as you will find out, it slots in perfectly and doesnt move once its in.
So to recap you need to get
bic biro
strong double sided sticky pads
30cm rca cable with small ends
13mm deep socket to remove the seat
If you do run cable under the carpet some black duck tape is awesome for sticking the cable to the car floor and also for wrapping the 2m of excess cable.
hope the length of this post hasnt put you off. it really is easy - I had never done anything like this and managed it without troubles.
