ARGH! UGH! ACK! OY MY HEAD IS HURTING FROM THIS THREAD!Sorry. Back to the issue at hand..
After your expenditures, I suggest keeping the car -- its impractical to do so but if you love the car enough, then the ownership and driving experience will be worth it. You should be able to get 270-300k out of it with PROPER care and staying on top of things that will (not might, I said will) go wrong.
The 99 Q is a nice, sharp car, but I spent $8k -total- on my 92 ($4k purchase and $4k fixing). If you dump the Q now, youve lost 5 grand. If you keep it, youll lose more.
This is the question that you must sit and contemplate:"Do I like this car enough to spend more, or should I suck it up and let it go?"
I kept mine, not because it was the sensible thing to do, but because I love every god damn thing about my Q45.
Have you considered an Infiniti I30 or Acura RL?
-Jesda