A friend of mine's apartment complex has an underground parking lot with a very steep ramp. As I was driving out of it today I heard something scraping my RX 350 underneath I drove about 100 miles afterward, no strange noise, no warning light on the dash, no puddle after parking. Am I in the clear? Could it have damaged something like the transmission link (AWD), or brake lines, etc? Thanks...

 

Probably need to just go out and take a look under the car and see if there is any evidence of the impact. This will give you the best idea of what was hit. You might want to also carefully check to make sure that there are not any fluids leaking under the car. I think you are probably OK. If it ever happens to you again, stop and check your car for damage immediately. If your car is leaking any substance don't use it. My son hit something in this Mustang and the first sign of trouble was when his engine was destroyed. Like you, he just drove on. The Mustang was a total loss.

 

Scraping something on a steep ramp, it's usually the bumper or some bracket related to the bumper that takes the hit. The approach and departure angles on the RX are pretty shallow (as compared to a 4x4 pickup or SUV), and that means the bumpers may take a beating.

Just look underneath with a flashlight and I'm sure you'll see some scrape marks. You can then judge whether anything critical has been damaged. Or post photos of the scrapes and we'll take a look too.