OK. So i just got back from a crazy weekend. It involved a retreat at Seneca Lake, OH. But ill start with some background info:

My car was starting to have this problem: on hot days after city driving then getting on the interstate the car would randomly drop out of OD and remain that way till i pulled over and restarted the car. Usually it would be fine the rest of the way. I assumed this was a heat related problem but the trans oil was full and still clean and red looking; and i havent been able to plug in my converter box to run the laptop on my car.

Back to this weekend; It is a 200 mile drive, and the drive there was rather uneventful, my baby made it all the way no problems besides the deep knocking i hear after long trips from the engine/transmission that no one has been able to find. But it has done that since we bought it at 40k miles and is now approaching 113k miles and its just a little louder.

The way home was a bit different. I had to get back to Cincy asap to get to work on time so I averaged about 80-85 or so. At one point I had to pull off the highway to adjust the antenna on my trunk. When I was accelerating back onto the interstate the transmission felt like it was surging and shuddering pretty much while getting up to speed. I was fully loaded with a full trunk and three other people in the car. I have AAA gold, so i was just praying to get within 100 miles of Cincinnati before it gave up the ghost.

Surprisingly she made it all the way back with hardly any other shuddering all the way back, but i never stopped either. When i got back into town the car would feel like a slingshot. I would accelerate from a stop it would be real sluggish then it waited till high RPM then the car would 'snap' up to speed. I just had the transmission rebuilt at 75k miles and I dont want to have to do it again, I'm just not sure if she'* worth another $1800 rebuild.

Then next day (today) the car seems to run and operate normally. The only real issues are after long trips and the blasted knocking that sounds so horrid. It even sounds like its coming from down low. So my question is: Do i save my money and go for the 1999 SSei of my dreams (i dont like the 00+ style as much but if i find a good enough deal...) when she finally goes out completely? Or do i put more money into a car that is rusting its life away already (its not major yet but bad enough in the right spots)?

I have a couple long trips scheduled in December and currently my mom'* car is the only one reliable enough to take them through the mountains of Tennessee, so i would have to take hers or rent one. But i seriously doubt i could have enough money by then for a new car.. so im thinking renting is probably the best option, and keeping my car till its dead. What are your thoughts?

Problems with my car:

Ahh, don't worry about it. I learned this the hard way: Don't worry about things until they actually happen. I know you might be thinking, well, I can't afford that, but I can't either, yet I'm still driving my car today with a slipping tranny. My tranny has been shuddering for 5k miles, but it hasn't let me down yet.

Haha, I just dont want it to die when in the hills of TN away from everything and 4 good friends in the car... And i dont want to have to take 'someone elses' car

Depending on how bad the rust is (surface rust, or the car is about to break in half rust), I say it might just be worth fixing. Just installing a transmission oil cooler might keep your temps down enough that your seemingly heat-related problems might go away, or lessen. If you grab one off of a junkyard SSEi or something, it would be dirt cheap, too.

I know exactly what you mean about rust in all the wrong places, and not knowing if it'* worth fixing a car. I had the same debate when the fuel pump was going out on my '89 LE, which had some pretty bad rust going on in the underbody. I ended up selling it, getting my '93 instead.

As long as it still moves though, I'd drive it and save your money for the next one.

i wouldnt be too concerned about it really, my trans has been shuddering for 35k on the 1-2 and it still hasnt let me down yet....

i say, fix the problems you can as inexpensively as possible, to prolong the life of your current Boonne. I am sure there are members not too far form you who would be willing to help out.
i would definitely start saving for the 99 though, too. (Which, y the way, is my dream too.)
Take it from someone who gave up on his Bonne, I miss it every day, and wish I would have tried to do more to keep her going.
But, you have to reach the point where you just can't put any more time or money into it either.

Really depends how you feel about the car. If it is worth it to you to keep it going, than do that, if you see no future with this car, then let it go and start saving. But dont be afraid to spend a little money on it on little things that can get big later. the longer it lasts, the longer you can save

Yeah, that is what I was trying to say.
Thanks for putting it a little more clearly.