I mean, there are plenty of ways to conjure legally-distinct names for brands. You could do it phonetically, replacing one or two letters to get something similar (e.g. Volno or Valvo), but this tends to come across a bit transparent and lazy, and your fake brand will never have the chance to stand on its own. You could look up how the original got its name: Volvo is latin for 'I roll', so scouring a latin dictionary for a similar phrase could do nicely (e.g. fugio 'I flee' or curro 'I gallop'), but it's no guarantee that the word will have the same punch as the original. Or, you could make up your own backstory entirely, and spin the name off of that. One of the founders of Volvo had the last name of Larson, perhaps the two alternate founders could have been the Larson brothers: Larson Bröder, or Labro, AB as it might have eventually become known.
Could I name it Segra, because OverPower made an swedish truck, and i guess its the same as Volvo (ykw, if i get perms)?