I know how you feel, giving up with it, getting bored, etc... A couple of months ago it seemed like I wouldn't get anywhere with the CRX and almost considered selling it and getting a 125cc bike, that's how desperate I was lol, now I'm so close to getting it on the road it nearly seems worth the wait. D2's aren't exactly great tbh. The bad handling could be down to something simple like worn bushes. If the bushes are worn then it wont matter how much adjustment and faffing around you do. For me it would all be down to money, what your current spec list is, and what you can afford. A RWD drift machine sounds fun but then you've got the running costs and everything, Starlets are very cheap to run even if you do need to spend a bit of money on parts to make it a decent car.