The first thing you have to do is to get, in writing, the ordinance that you are "violating". Find out exactly what it says, and when it was enacted, and WHY. Find out if it is legal if you add a large RV garage. You also need to find out how to sue the city/HOA/county to recoop the costs of widening your driveway. Then, contact the Good Sam Club; they have a lot of good info on fighting unfair RV ordinances.
We went through a similar issue back in '05 where I live. I had stored my MH on my property for 14 years, when suddenly I got a notice that I was in violation of city ordinance and had to move it. Unknown to me, the ordinance had been in effect for decades, but rarely enforced. A new council had decided to step up code enforcement, and RV owners were caught in the net.
The first thing I did was research; a lot of it. I researched the ordinance and when/why it was enacted. I researched other cities and their RV parking ordinances. I researched local storage lots in the area, and both the costs and the vandalism rates at those lots. I researched how many RV owners were in my city vs how much off-site storage was even available. I researched the fact that properties that were listed as having RV parking actually commanded higher selling prices than those without (so much for the argument that RVs lowered property values). I researched court cases. I researched supreme court cases and State Attorney General opinons (again, contact the Good Sam Club; lots of good info and tactics that have proven successful).
And then, I started to contact RV owners. In my case, the way the ordinance was written, if the RV could be seen from the street or even from a neighboring property, it was illegal. So I made flyers up alerting people to the stepped up enforcement and encouraging people to flood the next council meeting or risk losing their RV parking, and I put those flyers on the doors of every single home I could see that had an RV, trailer, boat, etc. visible.
It worked. The next council meeting was standing room only, filled past capacity with angry RV owners demanding action. The council immediately put a morotorium on the enforcement of the ordinance and agreed to work on the issue. It took more than 6 months of council meetings, planning commision meetings, and ad-hoc committee...but we kept the pressure on and won a reasonable RV parking ordinance that allowed the majority of us to keep our RVs.
BUT...and this is important...you will NOT win by yourself. You need others; lots of others, to join you in the fight. Councils could care less about 1 or 2 people complaining, but when 50 or 100 stand up in front of them, they take notice. And you need facts, not emotion. Present them with facts and figures that they can't dispute without looking like idiots (no elected official wants to look like an idiot in front of the public).
Obviously every situation is a bit different and will take a different amount of work/fight. Only you can decide whether the fight is worth it or not. Good Luck (and in the meantime, start looking for every little thing that your neighbor does that is in violation of any ordinance and turn them in for it! Nothing wrong with fighting fire with fire).