DesearÃa comprar este coche en caso de que la oferta siga en pie. Por favor comunÃqueme su domicilio y cuándo estarÃa dispuesto a realizar la transacción.
Remarks about the translation
He preferido traducir directamente del rumano que es una lengua más afÃn al español.
You're right that in Romanian it is in present indicative, but it sounds more polite with the conditional. I hesitated between "dirección" and "domicilio", but chose the latter. Either one would work. There are a couple of small errors in your translation, though: it's not "siendo" but "estando", since the phrase is "estar en pie". There is also an accent missing in "comunÃqueme" and it's "realizar" and not "realisar".
OK, thanks for the information! My Spanish is not flawless since I am not a native, anyway, it's always good to refresh your knowledge(hehe, "estar en pie" was logical, but I guided more after what sounds better, big mistake ) and to learn new things also!
p.s. It's not my translation that needs to be validated.