Okay, converting it out of Google Sketchup, and then cleaning up the model enough to use in SLRR, is going to be the tough part of the job here. Look up how to convert Google Sketchup to Wavefront .OBJ or another common format, first of all; this is one tutorial I found: https://help.sketchup.com/en/article/3000173
You're then going to want to import that into 3DS Max. If you can't use the import filters, that's a problem; if you do but you can't find ".OBJ" in there, then you might either have to install a newer version of Max than Max 5, or get a conversion program like Deep Exploration or something. Somehow, you have to get it into a format that 3DS Max can read.
Let me know when you get there. I've helped individual people start car conversion projects before (and I've been writing a tutorial on how to do it with Forza car models), but I want to make sure you're able to at least get there first.