ford focus speaker wire lengths

I'm building my own VenHaus speaker wires for the Focus, and I was wondering if I could get some info on speaker wiring length..If anyone knows the approximate lengths from a hatch mounted amp to the rear and front speakers, that would be awesome!I was guessing maybe 7' for the rear speakers, and maybe 15 or 17' for the fronts?

I'll probably run the fronts up thru the center of the car, then across to the doors and thru the jambs...I don't want to spend HOURS building wire only to have it too short...and it's rather expensive making lengths longer than you need...Oh, VenHaus speaker wire, for those of you who don't know, is Cat5 network cable (because it's single strand copper), and the particular type used is individually coated in Teflon in twisted pairs...You need to braid multiple pairs together (27 pairs!), to reduces any asymmetrical field interactions and to get a sufficient gauge (equal to 10g!)...You end up with some VERY fine speaker wire with audio characteristics equalling and rivalling that of VERY expensive speaker wire...Audioquest Midnight, Straightwire Maestros, Kimber 8TC...