I had replied early but maybe it didn't go through....
Synthetic oil is fine. I actually prefer it, but I also have a TDI. I believe with your's being a 2005 you have to use synthetic. I could be wrong. Either way, I'd keep using it, it's better for the car.
Get a panzer plate for sure! I don't think your warranty will replace your engine if you bust your oil pan because you didn't have a cover. I'm sure that's in your records somewhere and they could opt not to get you a new engine. Then you'd just have a shell of a good car. Don't do that.
Panzer Plate they are kinda pricy but they are worth your weight in gold!!!