We don't know for sure.  Ebenezer has an old, beat-up truck from WWI/WW2, but he's 300 years or so old.

This is an option in the books though for hexing at least, and I'd lean towards it.  Just would say Ebenezer's really good at control. ;P

You can extend an evocation by casting the spell again and getting more duration.

What she probably did is one of two things:

1) Kept casting the Evocation every few exchanges to keep it going and the GM said as it's out of combat, she doesn't have to worry about the stress from doing so, she'll just be distracted if combat hits.
2) Once she was hidden, do a quick thaumaturgy to extend it in some way.

Least if it's the scene I'm thinking of.  I lean towards 1, though.

I admit, I'm not sure I like the idea of -everything- being unable to be made 'always on'.  There's a difference between systematically always on and in-setting.  The books never even imply that Harry's coat is limited use, unlike his rings, which definitely are.  Just that he has top off the enchantment every once in a while.

But we'll see how it works out.

Sounds like he wants the catch to be something he does, which isn't what a catch is -- at least by my reading.  A catch is something someone can do to bypass it.  Not something you do that makes you lose the protection.

You'd need something like silver, cold iron, and so on, I'd think.  Even a +0 catch should be something -other people- can do.

You can use Sponsored Magic for that.  It fits the books, really.  Harry starts using Sponsored Magic a lot as he gets in the big leagues, ending up really pissed off a lot (Hellfire) or having to do Uriel's stuff (Soulfire).

And of course the gripping hand is that we haven't seen anyone wearing enchanted body armor yet, have we? Is that because of traditions/closed mindedness on the part of wizards we deal with? Aside from Harry, who hasn't had the resources/funds for actual armor throughout most of the series, it's pretty well established that most of the White Council is kind of stuck in their ways.

Doesn't Carlos wear Kevlar with his grenades and things?  I /think/ I recall a reference.

Kevlar's only Armor 1-2, anyway.  Personally, I wouldn't make a big deal of it, but I would, if they were using such a material, maybe add +1 or +2 to the wizard's Lore for that item only.  I'd also make a note that if they're stopped, police will be curious.  Even if not illegal, they'll wonder why the guy in the periphery of the case is wearing kevlar.  I think the tradeoff of 'a bit of a boost' verses 'you have to possibly deal with police' is a fair tradeoff.

Edit: Don't know if this works, actually.  Mostly because +1-+2 isn't enough to actually have an impact for armor.  Maybe rather than complicating stuff, just eyeball.  Say that a 'suitable material' gives +1 to the final value, and call it a day.

I'd definitely be willing to play -- especially if it's done via some sort of chat or MUSH medium, which is what I prefer.   But will do PbP too.