First of all don't apologise for your english, I cannot speak Argentinian at all so you are one up on me!
You do not say what tyres you are running, on my 98 when I used Dunlop 207's they would wave, cup, feather whatever you want to call it. When I changed to Michellin Pilot Sports the problem disapeared. Everybody has favorite tyres although I will never use Dunlop again because of the problem you are describing.
This of course may not be your problem although if the wave wear patterns are the same on both sides of the front tyre I do "NOT" believe an alignment problem is the cause.
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