Collecting Letter Scraps, Space ship parts

I am currently trying to collect the letter scraps (to eventually get the achievement for A mystery solved worth 15G points) and the space ship parts (another 15G points for getting that) currently i picked up 20/50 letter scraps and just one space ship part, i am following the IGN gameplay walkthrough to help me with that but i have spend like close to 4 hours getting these and this is what i do currently.

• Check the video.
• mark the location on my map from the video.
• collect.

Has anyone here got these achievements and is there any simpler route for accomplishing these?

Solution 1:

By far the easiest way to get all Letter Scraps and Spaceship Parts is by linking your game to your Rockstar SocialClub account and use the interactive Map Legend to keep track of the collectibles you've found, and those you haven't yet found.

The map takes a little while to update and your console needs to be online for it to work at its fullest.

Solution 2:

For finding collectibles and other items: Here is an interactive map by IGN of Los Santos and Blaine County

You can filter the collectibles by UFO parts. This may be faster than your current approach.