Tires, what are you using?

[TPEHAK]

https://vespamotorsport.com/can-i-ri...n-the-freeway/

[BambamXB12r]

“In California, any scooter with 150cc of displacement or more is legally classified as a “motorcycle” and all motorcycles are freeway legal (see California vehicle code section 400). Any scooter with less than 150cc of displacement is not freeway legal, therefore, even though you still need a motorcycle license to ride a scooter in this class.”
“In truth, most150cc scooters are too small for serious freeway riding for the following reasons”
“For these reasons, we recommend a scooter in the 300cc class or more for serious freeway riding, including the following models: GTS 300 Super, GTS 300, GTV 300, GTS 300 Super Special Edition, Piaggio BV350, MP3.”
All quotes from the website you posted. Plus with your great mod ideas you could have it legal in Cali in no time.