Yes, as long as whenever you return to iRacing you renew your existing account and do not create a new account (with a different email address).
If your account is a direct iRacing account, it must be renewed through iRacing.
If your account was originally opened through Steam, it must be renewed through Steam.
iRacing and Steam have completely separate purchasing systems.
All previous cars and tracks purchased will be as you left them as well. Whenever you are ready to return, simply log into http://members.iracing.com (or www.iracing.com and click the Sign In button at the top right) with the same email address and password as you did before and it should prompt you to renew your existing iRacing account.
Any progress on your racing licenses will also be on your reactivated account.