Robert Rodriguez imagines up the fourth film in the increasingly goofy Spy Kids series. At least Alexa Vega and Daryl Sabara have the good sense to jump in the back seat and let new kids Rowan Blanchard and Mason Cook take over. They play stepkids to retired spy Jessica Alba. Naturally, they're called upon to help mom battle the villainous Time Keeper (Jeremy Piven) with the aid of a talking dog (voiced by Ricky Gervais) and a bunch of rejected props from Carrot Top. The whole thing is in "4D." In case you were wondering, the fourth "D" is Aroma-Scope, a scratch-and-sniff card that allows viewers to smell the movie as well as see it. If only Rodriguez can resist the urge to include farts. ... Oh, nope, he can't.89 minutes PG.