macgirl, imho i prefer the tiefen over 303. i've tried the 303 and can't stand it; washes off way too easy. i only recoat my exterior trim about once every 2 months with the tiefen. the only time i've ever gotten runoff from the tiefen is when it's rained the same day i put it on. any time it's been able to sit a day or 2 w/out rain it's lasted for weeks. all i do is wash my truck with either 1z exclusiv shampoo or now the perls shampoo and qd everything and i'm good to go. no need to reapply the tiefen each time. the durability of the tiefen on tires varies depending on the wall surface of the tire(flat,riges,raised letters, etc.). the new stuff is not a new tiefen but something alltogether different. it is called Kunstoff Intensiv Pflege and if i remember correctly what michael told me it's only for exterior trim and lasts longer than tiefen. i'd read you the label but it's in german. as far as your interior the tiefen would work for everything but the leather - it's not ph balanced for leather, but it won't hurt it either. you'd need the leather care for that - good stuff! i don't think any of it will be available in gallon sizes, but you don't need to use a whole lot. a little goes a long way. have you tried the tiefenpfleger? if not i may be able to send you a sample to try and the leather care too. pm me or send me an email about that.