Being just for the earlier vehcles is definately a good indicator.
There's so much marketing goblety-gook these days its harder to know whats good and what's not.
Some key things I look for are unfortunately process of elimination
- it claims to be universal, it can't be, and certainly not ideal.
- if it says 'phosphate free' then its for european spec, not what we want.
The phosphates are one of the inorganic corrossion inhibitors that quickly protects. Apparently Europe has a lot more hard water than we do, and phosphates can drop out of solution when mixed with high mineral water. Its one of the reasons that even here, mixing with distilled water is best.