So, the original card in my Dell 1318 was a Broadcom a/b/g/n card. It was nice that it had a but it was a Broadcom so it doesn't play well. So, I picked up an Atheros b/g/n card (ar5bxb72 err looks like it is a/b/g/n) which is actually out of a MAC. The new card arrived with 3 antenna connectors. My Dell only had 2 antennas, so naturally I hit ebay and bought another antenna.
Now, the fun came with installing the new antenna. Suprisingly Dell actual puts the service manual online:
Documentation
so I proceeded to tear the new laptop apart. Then the fun came. I realized that the two antennas I bought off ebay had some heat shrink tubing holding them together. One was 72mm the other 60mm in length. I got out the razor blade and proceeded to put a nice slice in the shield of the 72mm. Thanks alot Murphy! Luckily I managed to route the shorter cable with not a mm to spare in length. There's actually a spot on the back of the display where there is no shielding a perfect spot for the antenna. The existing antennas are the short regtangular (ceramic?) type along the top edge of the display.
All-in-all it went quite easily. The only question is:
On a card where the antennas are labelled 0, 1, 2 which one is which? I assumed that the mimo antenna would be 1 since it's in the middle. If not I'm screwed since the cable won't reach to 2.