<?xml version="1.0" ?>
<audio_patches>
    <!-- No upgrade installed, patch nothing. -->
    <audio_patch max_stage="0">
    </audio_patch>

    <!-- Stage 1 upgrade. -->
    <audio_patch max_stage="1">
        <prop name="EngineVolume" data="0.8" />
        <prop name="DistortionMap" data="0" />
        <prop name="SuperChargerMap" data="" />
    </audio_patch>

    <!-- Stage 2 upgrade. -->
    <audio_patch max_stage="2">
        <prop name="EngineVolume" data="0.75" />
        <prop name="DistortionMap" data="1" />
        <prop name="SuperChargerMap" data="" />
    </audio_patch>

    <!-- Stage 3 upgrade. -->
    <audio_patch max_stage="3">
        <prop name="EngineFrequencyMultiplier" data="1.01" />
        <prop name="EngineRevRangeMultiplier" data="1.06" />
        <prop name="EngineVolume" data="0.8" />
        <prop name="DistortionMap" data="1" />
        <prop name="SuperChargerMap" data="" />
    </audio_patch>

    <!-- Stage 4 upgrade. -->
    <audio_patch max_stage="4">
        <prop name="EngineFrequencyMultiplier" data="1.02" />
        <prop name="EngineRevRangeMultiplier" data="1.12" />
        <prop name="EngineVolume" data="0.8" />
        <prop name="DistortionMap" data="1" />
        <prop name="SuperChargerMap" data="" />
    </audio_patch>
</audio_patches>