Ricardo, you'll have the benefit of knowing that many of us did not wait for the warranty to expire to start experimentation! Nor do most upgrades actually mess with typical warranty concerns. There's a legion of ideas in the many threads on this site but the most popular seem to be: Dynomat vibration/sound insulation, removing the cats/baffles or 'Stage 1' exhaust and intake, add an oil cooler, add an 'extended' fan switch, Ohlin/Spax adjustable shocks, better tires, add a dead pedal, add a set of fog/driving lights. if you really want to push it, maybe add cams (Stage !! or !!!) and a custom ECU tune.
Given the inherent fragility of the 'final mile' (Centa), there's only so much one can or should do to increase its load, nor (IMHO) does this toy actually need more HP/torque!

. Helping the engine to breathe and to cool better, to be more responsive and making the ride more comfortable yet controlled seem to be the goals of modifications. Open your wallet, clear your calendar.....enjoy!