I'm on the last question on the volvo treasure hunt and can't get it for the life of me!?

Question

'All eight but one will see the same
For you to find that final name' Help will be greatly appreciated

Answer 1

The keyword for Port Royal is obtained by using the eight eyed card and placing the upper left most eye over the s from the location hollow trees and turning the card at a 45 degree angle (approximate) towards the serpent.
The letters shown in the eyes are:
Upper Left - s (from hollow treeS)
Upper Right - s (from Six islands)
2nd Row Left - s (from shallowS)
2nd Row Right - s (from six iSlands)
3rd Row Left - s (from horSe bay)
3rd Row Right - s (from six islandS)
Bottom Left - s (from South cape)
Bottom Right - t (from serpenT)

Reading from left to right, top to bottom, you arrive at: ssssssst

To solve this puzzel you must go back through the previous locations and find the obvious letters and numbers written somewhere.

1) Sargasso Sea - Nothing
2) Bermuda - 2 on box lid, 5 on plate
3) Madiera - 5 on door, 8 on wine cask
4) Tropic of Cancer - N
5) Saint Helena - 7
6) Saint Mary - 7
7) Pulau Jong - 1
8) Diomede - Nothing
9) Isla Mas A Tierras - 3 on rocks
10) Cape Horn - Nothing
11) Cozumel - W
12) Isla Culebra - Nothing
13) Port Royal - Nothing

Using the numbers derived from each of the locations (and the order in which they were obtained, if more than one number was obtained, such as on Bermuda and Madiera)

2 - Bermuda
5 - Bermuda
5 - Madiera
8 - Madiera
N - Tropic of Cancer
7 - Saint Helena
7 - Saint Mary
1 - Pulau Jong
3 - Isla Mas A Tierras
W - Cozumel

Put them together and you arrive at:
2558N7713W which will take you... somewhere.

Answer 2

is it something to do with sea? 8 but one = 7. 7 sea's?

Answer 3

line up the top left circle with the s in trees...

Answer 4

XC90 is your final sight if you win............
Good luck.