1。全车贴膜。
If you are talking about windows..., not really useful until you are living in Texas.

2。底盘装甲，好象在底上喷上4层作用不同的塑胶或者树脂。用以保护底盘。
Scam. regular car wash would take care of it, if you are living in NE. Salt does eat cars, and they use a lot of salt in winter at area with heavy snow.

3。发动机护板，就是因为现在很多车的发动机下的底下都没有板了，装块板保护发动机。
-- scam.

4。光触媒，据说是防止新车的气味危害人体用的。
-- scam.

5。全车隔音，就是用进口的材料，在顶部，底部，车后箱里贴上，这样增加乘坐的舒适程度。
another scam.

6。汽车封釉，用来保护油漆的。
not sure what do you mean, certain treatment can make it looks better, but not to protect the paint. Also你可以自己抛光打蜡。