no oil cap for 2 months!
 

I always change the oil myself, but last time I had the dealer do it because I received a coupon for a "FREE" oil change in the mail so I said why not? It will save me $15. Yesterday I decided to check the oil level while I was pumping gas and guess what? There was NO oil cap! I have been driving like that for 2 months! The engine sounds and runs great. The oil level was a lil low, but nothing alarming, maybe 1/2 qt. low. The dealer was the last one to work on my car. Nobody else touches my car, but me and the dealer sometimes. So I went to Pep Boys and bought a cheap oil cap and some oil and filter and did an oil change myself. I called the dealer this morning and told them. I was ready for them to BS me, but they did not and they apologized and offered me free oil changes until my warranty expires. My car has 11k miles.
My question is, could the engine be damaged or compromised in any way? What should I do? I am trying to get an extension on my warranty, but I don't see that happening.
I talked to several of my friends and they all seem to think the engine is OK. I heard people said that they dropped nuts and bolts into the engine by accident while swaping cams, etc and nothing happened and later when doing and oil change they would come out. Some what do you guys think?

Moral of this story...learn to do all your own work lol....seriously though your motor shoudl be fine....as long as no dirt got in there and got in the cam races if it did then it shoudl be acting like sandpaper on your cam journals but you luck y cause our cams have oil spuirters as most cams do that spray oil in the cam journals.

Would you want to go back to the same dealer who forgot something as simple as the oil cap? They could give you a lifetime of oil changes, but if they're going to do this, it's not worth it. Whether you take them up on the offer is up to you. Your engine should have blown out the oil through the hole, did you notice that there was oil underneath your hood? The 1/2 quart you are missing may be normal, as most 4 cylinder engines do consume oil under normal circumstances.

oil does have a certain amount of evaporation just like any other petroleum product. It isnt a squirt gun however, so it shouldnt have regurgitated oil into the engine compartment unless you ran the crap outta the car and it boiled over or you went off-roading and it splashed out. Now I don't know about your friends with nuts and bolts in the cylinders but they are lucky they didnt jam open a valve. At the very least the gouged the hell outta the piston and cylinder walls. They are very lucky but there engine may develope problems over time now. You see how paranoid people are about letting a grain of anything into the engine but something that size and that much mass and i bet it sounded like the a-typical knocking and pinging foud is some of our pro's :)