I spent over 30 years taking apart cutting apart vehicles to repair them, after they were wrecked.
Most of that was in the hay day of rustproofing.
The first thing you learn, is 90% of these rust-roofing outfits are a complete, and total rip off. I am talking about they drill hole, and give one shot right where the hole is, and putting a plug in.
The next 8% are decent places, trying to do a decent job, but still failing to get the material where it needs to be.
The final 2% do it right.
The majority of cars, eventually needed rust repair, from the moisture that collected around the rustproofing plugs. Which is ironic, since that was done to stop rust.
I remember one Dodge Caravan, that I cut the side off of which the customer said was rustproofed when new, and taken back every year, for the warranty required, paid touch up. There was almost no rustproofing material inside it. The Irate customer who stop by and saw this, called the rust-proofers to my shop to see it, and they said the reason we can't see it is, ...get ready, this is good: ... We could not see it, because it was invisible!
The whole scam was predicated on people selling their car before they made a warranty claim. The few claims they paid for rust repair, were peanuts, compared to the money they charged, for treatments they never actually did.
Cars have today, (Chrysler, and Mercedes were the last holdouts, but surely have given in and switched since I retired), have galvanized sheet metal. The bodies on most vehicles, with normal driving, will last 12-15 years without much maintenance.
My 1997 Villager, is just starting to get holes in it this year. 17+ years, is pretty good, considering I did not rust proof it. (I always did my own).
So, my recommendation is, undercoating is not a bad idea, if you plan to keep it, more than 10 years. For those who don't understand the difference, undercoating is spraying the bottom of the car only. Those areas receive minimal protection from the factory. And, you can see it when they are done, so they can't rip you off.
However, I would not suggest most people need to spend money on rustproofing. Because, you are probably going to get ripped off anyway.
And, forget about that electronic crap too. It's been around since the early 80's. I have seen it over, and over, and over. It's a real nice "feel good" thing. But, it does not work.
P.T. Barnum was right. :thumbsup:
The biggest two things you can do to make your car last, is to NOT wash it, and put it in the garage. It stays wet for days in cracks, and crevices. And, do NOT wash it when its really cold. It does more harm than good. The salt is not doing anything at those temperatures, but the moisture you just put in all the crevices, and inside the doors, can do damage each time it freezes and expands. Wait until it warms up, or your car is already all wet due to thawing, to wash it.
