I have a 2008 Suzuki with about 34,000 on it. I just recently did a coolant exchange, strict exchange. I do NOT trust flush machines at all. I use ZEREX conventional green as the very basic ethylene glycol is whats req for my zuke. I noticed Zerex (as well as many other brands) offers a chemical based flush, a protectant (assume its an additives bundle) and a Super concentrated chemical flush. Has anyone used these products at all? Is it worth it to add the protectant after the flush or is it overkill. Right now all I've done is drain, flush with water, cycle, purge and refill. The car's pretty new so no deposits or "gunk" but if these products do more for the cars life I'd be interested to know.