Quite early in Sideswipe's original Tech Specs, we are told that he is "less cold-blooded" than his twin brother Sunstreaker. Given that we've already seen that Sunstreaker is rather a nasty piece of work (at least, for an Autobot), such a statement may well be damning with faint praise. The fact is, Sideswipe is indeed a fighter who is by no means above using "underhanded tactics" (another phrase straight out of those Tech Specs).
Sideswipe was one of several Transformers (including the aforementioned Sunstreaker) that turned into a Lamborghini of some type or another (Sideswipe is specifically a "Countach" model). Lamborghinis were apparently very popular in the 1980s among those who paid attention to such things, but I have to confess that I'd never actually seen a Lamborghini in real-life until my arrival in Southern California in the late-90s! I imagine that part of the reason for this is the fact that Lamborghini's very extremely expensive. One could easily pay $100,000 for the model of vehicle that Sideswipe represents back in the 1980s (and that's in 1980's dollars!).
Sideswipe definitely has a strong ego, as might be expected of a robot that turns into such a fancy alternate mode. However, Sideswipe's ego is much more focused on his fighting prowess than it in on keeping himself in pristine condition (that's Sunstreaker's department). In fact, one of Sideswipe's most well-known abilities is the fact that his arms act as pile drivers, enabling him to punch through rock and create tunnels. Not something that someone who cares about keeping his paint free from chipping would be likely to do! Of course, readers of Sunstreaker's article may remember that there was a likely bio-swap sometime early in the development process. This is especially relevant in Sideswipe's other well-known ability, that of possessing a rocket backpack, making him one of the few early Autobots with an explicitly-stated (if limited) ability to fly. Good luck finding any features on the toy itself that relate to that purported feature! Nonetheless, these are the characterizations and abilities that have become a part of the fiction, and there are more than a few examples of Transformer characters revealing whatever part or equipment they might need, seemingly out of thin air, whenever a plot might require it.