I have noticed that the game designers did a messy job at converting the blip textures for the PC version. So I converted them from the PS2 version in an uncompressed format as the file is already very small. You do not lose any quality at all as the blips are 16x16 in both versions.
The blip textures from the PS2 are the originals and it looks like there was put much more thought into them while the PC blips look badly converted and lack detail.
So here you get it like it should have been in the first place.
There are two versions:
PS2 Blips (Uncompressed)
PS2 HUD+Blips (Uncompressed)
The upper one only features the much better blips while the second version features a whole conversion including the lower quality radar ring texture and textures only relevant to PS2 gamepad users.