I just bought my system but didnt realize there were tweeters in the doors of my olds lss 99'. Im a little ow on cash do you think the 5.25 coaxials with the 6x9' in the back would sound alright or should i really consider getting seperate tweeter. All my system is MTX.

Tweeters are worth it IMO, even though you do have coaxials already. You wouldn't want to add them if you already have coaxials, because that would sound weird. If you can return them, go for mids and tweets, you won't regret it.