Manifold/header/muffler/tail Pipe problems of the 2000 Nissan Quest

I have had to change my headlights repeatedly (going on 3rd time) and my tail light (1 time). In addition, I have problems with my accelerator pedal; it seems to stick, until I apply enough pressure then it takes off abruptly fast, had these same problems (with replacing head and tail lights and accelerator) when I had my 1993 Nissan Quest, but dismissed them. Now I see a correlation with the 2000 Quest I have now. The low profile of my Quest caused my transmission pan to leak fluid, because of a dip in the road. Constant problems when parking due to the front end of my Quest being too low and scraping the curb. Problem with heating system in the rear, only blows out cold air regardless of setting it to heat. There is a very strong gas smell when my car is running (this was also experienced in my 1993 Quest) only compact incident was when my tranmission pan cracked going down the street and going down a dip in the road (not a pot hole). Other than these things I have been very pleased with my purchases, very reliable but these are a few things I've noticed and hope that you will consider my concerns to further be investigated.