In the manga, Vanguard Sonic was used by Retsu until the Great Japan Cup. He only upgraded his mini4wd prior to the WGP. To be honest, I wish V-Sonic were used on the initial races of the WGP (at least in the manga). Its contemporaries Spin Cobra and Neo Tridagger ZMC and to a lesser extent, Proto Saber Evolution were effectively used in many races of the WGP before they changed to Spin Viper and Rising Trigger. Nonetheless, it's nice that you have them all including Jiromaru's mini4wd. For the moment, I only have the Neo Tridagger ZMC.