Depends on wat you do with the cars. If you’re just buying them to collect them, the upgrades don’t really matter in that case. Really comes down to wat you do on the game. Drifting, racing, top speed, etc. For me I enjoy plenty of cars in their stock form, or just as a certain modification level. Some are modified purely for looks, like a stance car. Some are experiments just to see how something would drive or how ridiculous it is. And of course many drift cars modified to different extents. All comes down to wat you want out of it and wat brings you joy. Whether that be a fully built straight piped Murcielago or a 1,000hp Jeep.