IF your final goal is to go racing. Meaning you intend to go racing within 6months to a year get the best TC you can afford and save all kinds of money by not hopping up a sub standard car. Dont get a sport version or a non current year model to save a few bucks and then spend more the the pro version in the end hopping it up later.
With that said there is nothing wrong with the TC4 but dont assume that because the TC5 is the current car that it makes it not suitable for starting nor does it make the TC4 absolete, but the touring car scene has almost all turned to belted cars... So you may want to follow the trend.
Bottom line you can be competative with a FACTORY TEAM TC4 or TC5.
PS the best thing to do is actually go racing, we get lots of guys locally who shy away from race night to practice and find that once they actually go racing the learn alot more then running laps alone on practice days.
"Without Rules its just Backyard Bashing!"